Init and save / restore of PMCR_EL0 / PMCR

Currently TF does not initialise the PMCR_EL0 register in
the secure context or save/restore the register.

In particular, the DP field may not be set to one to prohibit
cycle counting in the secure state, even though event counting
generally is prohibited via the default setting of MDCR_EL3.SMPE
to 0.

This patch initialises PMCR_EL0.DP to one in the secure state
to prohibit cycle counting and also initialises other fields
that have an architectually UNKNOWN reset value.

Additionally, PMCR_EL0 is added to the list of registers that are
saved and restored during a world switch.

Similar changes are made for PMCR for the AArch32 execution state.

NOTE: secure world code at lower ELs that assume other values in PMCR_EL0
will be impacted.

Change-Id: Iae40e8c0a196d74053accf97063ebc257b4d2f3a
Signed-off-by: David Cunado <david.cunado@arm.com>
diff --git a/include/lib/aarch32/smcc_helpers.h b/include/lib/aarch32/smcc_helpers.h
index 1bc8438..53f1aa4 100644
--- a/include/lib/aarch32/smcc_helpers.h
+++ b/include/lib/aarch32/smcc_helpers.h
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2016, ARM Limited and Contributors. All rights reserved.
+ * Copyright (c) 2016-2017, ARM Limited and Contributors. All rights reserved.
  *
  * SPDX-License-Identifier: BSD-3-Clause
  */
@@ -21,7 +21,8 @@
 #define SMC_CTX_SP_MON		0x7C
 #define SMC_CTX_LR_MON		0x80
 #define SMC_CTX_SCR		0x84
-#define SMC_CTX_SIZE		0x88
+#define SMC_CTX_PMCR		0x88
+#define SMC_CTX_SIZE		0x8C
 
 #ifndef __ASSEMBLY__
 #include <cassert.h>
@@ -73,6 +74,7 @@
 	u_register_t sp_mon;
 	u_register_t lr_mon;
 	u_register_t scr;
+	u_register_t pmcr;
 } smc_ctx_t;
 
 /*