Re-factor header files for easier PSCI library integration

This patch re-factors the following headers to make it easier to
integrate the PSCI library with an AArch32 Secure Payload :

  *  bl_common.h : The entry point information and the param
     header data structures are factored out into separate
     headers ep_info.h and param_headers.h
  *  psci.h : The PSCI library interfaces are factored out
     into the new header psci_lib.h
  *  context_mgmt.h : The header file is modified to not include
     arch.h when compiled for AArch32 mode.

No functional changes are introduced by this patch.

Change-Id: I5e21a843c0af2ba8e47dee4e577cf95929be8cd4
Signed-off-by: Soby Mathew <soby.mathew@arm.com>
diff --git a/include/lib/el3_runtime/context_mgmt.h b/include/lib/el3_runtime/context_mgmt.h
index 676973c..ca868dd 100644
--- a/include/lib/el3_runtime/context_mgmt.h
+++ b/include/lib/el3_runtime/context_mgmt.h
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2013-2016, ARM Limited and Contributors. All rights reserved.
+ * Copyright (c) 2013-2017, 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:
@@ -31,7 +31,9 @@
 #ifndef __CM_H__
 #define __CM_H__
 
+#ifndef AARCH32
 #include <arch.h>
+#endif
 
 /*******************************************************************************
  * Forward declarations