Remove build option `ASM_ASSERTION`

The build option `ENABLE_ASSERTIONS` should be used instead. That way
both C and ASM assertions can be enabled or disabled together.

All occurrences of `ASM_ASSERTION` in common code and ARM platforms have
been replaced by `ENABLE_ASSERTIONS`.

ASM_ASSERTION has been removed from the user guide.

Change-Id: I51f1991f11b9b7ff83e787c9a3270c274748ec6f
Signed-off-by: Antonio Nino Diaz <antonio.ninodiaz@arm.com>
diff --git a/plat/common/aarch64/platform_mp_stack.S b/plat/common/aarch64/platform_mp_stack.S
index e3063d1..322e3bb 100644
--- a/plat/common/aarch64/platform_mp_stack.S
+++ b/plat/common/aarch64/platform_mp_stack.S
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2014-2016, ARM Limited and Contributors. All rights reserved.
+ * Copyright (c) 2014-2017, 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:
@@ -131,7 +131,7 @@
 	 * -------------------------------------------------------
 	 */
 func_deprecated platform_get_stack
-#if ASM_ASSERTION
+#if ENABLE_ASSERTIONS
 	mrs	x1, mpidr_el1
 	cmp	x0, x1
 	ASM_ASSERT(eq)
@@ -150,7 +150,7 @@
 	 * -----------------------------------------------------
 	 */
 func_deprecated platform_set_stack
-#if ASM_ASSERTION
+#if ENABLE_ASSERTIONS
 	mrs	x1, mpidr_el1
 	cmp	x0, x1
 	ASM_ASSERT(eq)