Introduce `el3_runtime` and `PSCI` libraries

This patch moves the PSCI services and BL31 frameworks like context
management and per-cpu data into new library components `PSCI` and
`el3_runtime` respectively. This enables PSCI to be built independently from
BL31. A new `psci_lib.mk` makefile is introduced which adds the relevant
PSCI library sources and gets included by `bl31.mk`. Other changes which
are done as part of this patch are:

* The runtime services framework is now moved to the `common/` folder to
  enable reuse.
* The `asm_macros.S` and `assert_macros.S` helpers are moved to architecture
  specific folder.
* The `plat_psci_common.c` is moved from the `plat/common/aarch64/` folder
  to `plat/common` folder. The original file location now has a stub which
  just includes the file from new location to maintain platform compatibility.

Most of the changes wouldn't affect platform builds as they just involve
changes to the generic bl1.mk and bl31.mk makefiles.

NOTE: THE `plat_psci_common.c` FILE HAS MOVED LOCATION AND THE STUB FILE AT
THE ORIGINAL LOCATION IS NOW DEPRECATED. PLATFORMS SHOULD MODIFY THEIR
MAKEFILES TO INCLUDE THE FILE FROM THE NEW LOCATION.

Change-Id: I6bd87d5b59424995c6a65ef8076d4fda91ad5e86
diff --git a/include/lib/psci/psci_compat.h b/include/lib/psci/psci_compat.h
new file mode 100644
index 0000000..3554667
--- /dev/null
+++ b/include/lib/psci/psci_compat.h
@@ -0,0 +1,116 @@
+/*
+ * Copyright (c) 2015-2016, ARM Limited and Contributors. All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ * Redistributions of source code must retain the above copyright notice, this
+ * list of conditions and the following disclaimer.
+ *
+ * Redistributions in binary form must reproduce the above copyright notice,
+ * this list of conditions and the following disclaimer in the documentation
+ * and/or other materials provided with the distribution.
+ *
+ * Neither the name of ARM nor the names of its contributors may be used
+ * to endorse or promote products derived from this software without specific
+ * prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
+ * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#ifndef __PSCI_COMPAT_H__
+#define __PSCI_COMPAT_H__
+
+#include <arch.h>
+#include <platform_def.h>
+
+#ifndef __ASSEMBLY__
+/*
+ * The below declarations are to enable compatibility for the platform ports
+ * using the old platform interface and psci helpers.
+ */
+#define PLAT_MAX_PWR_LVL	PLATFORM_MAX_AFFLVL
+#define PLAT_NUM_PWR_DOMAINS	PLATFORM_NUM_AFFS
+
+/*******************************************************************************
+ * PSCI affinity related constants. An affinity instance could
+ * be present or absent physically to cater for asymmetric topologies.
+ ******************************************************************************/
+#define PSCI_AFF_ABSENT		0x0
+#define PSCI_AFF_PRESENT	0x1
+
+#define PSCI_STATE_ON		0x0
+#define PSCI_STATE_OFF		0x1
+#define PSCI_STATE_ON_PENDING	0x2
+#define PSCI_STATE_SUSPEND	0x3
+
+/*
+ * Using the compatibility platform interfaces means that the local states
+ * used in psci_power_state_t need to only convey whether its power down
+ * or standby state. The onus is on the platform port to do the right thing
+ * including the state coordination in case multiple power down states are
+ * involved. Hence if we assume 3 generic states viz, run, standby and
+ * power down, we can assign 1 and 2 to standby and power down respectively.
+ */
+#define PLAT_MAX_RET_STATE	1
+#define PLAT_MAX_OFF_STATE	2
+
+/*
+ * Macro to represent invalid affinity level within PSCI.
+ */
+#define PSCI_INVALID_DATA -1
+
+#define psci_get_pstate_afflvl(pstate)		psci_get_pstate_pwrlvl(pstate)
+
+/*
+ * This array stores the 'power_state' requests of each CPU during
+ * CPU_SUSPEND and SYSTEM_SUSPEND which will be populated by the
+ * compatibility layer when appropriate platform hooks are invoked.
+ */
+extern unsigned int psci_power_state_compat[PLATFORM_CORE_COUNT];
+
+/*******************************************************************************
+ * Structure populated by platform specific code to export routines which
+ * perform common low level pm functions
+ ******************************************************************************/
+typedef struct plat_pm_ops {
+	void (*affinst_standby)(unsigned int power_state);
+	int (*affinst_on)(unsigned long mpidr,
+			  unsigned long sec_entrypoint,
+			  unsigned int afflvl,
+			  unsigned int state);
+	void (*affinst_off)(unsigned int afflvl, unsigned int state);
+	void (*affinst_suspend)(unsigned long sec_entrypoint,
+			       unsigned int afflvl,
+			       unsigned int state);
+	void (*affinst_on_finish)(unsigned int afflvl, unsigned int state);
+	void (*affinst_suspend_finish)(unsigned int afflvl,
+				      unsigned int state);
+	void (*system_off)(void) __dead2;
+	void (*system_reset)(void) __dead2;
+	int (*validate_power_state)(unsigned int power_state);
+	int (*validate_ns_entrypoint)(unsigned long ns_entrypoint);
+	unsigned int (*get_sys_suspend_power_state)(void);
+} plat_pm_ops_t;
+
+/*******************************************************************************
+ * Function & Data prototypes to enable compatibility for older platform ports
+ ******************************************************************************/
+int psci_get_suspend_stateid_by_mpidr(unsigned long);
+int psci_get_suspend_stateid(void);
+int psci_get_suspend_powerstate(void);
+unsigned int psci_get_max_phys_off_afflvl(void);
+int psci_get_suspend_afflvl(void);
+
+#endif /* ____ASSEMBLY__ */
+#endif /* __PSCI_COMPAT_H__ */