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been replaced by `ENABLE_ASSERTIONS`.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/Makefile b/Makefile
index d03c2bf..31460d4 100644
--- a/Makefile
+++ b/Makefile
@@ -50,10 +50,13 @@
 # Default values for build configurations, and their dependencies
 ################################################################################
 
+ifdef ASM_ASSERTION
+        $(warning ASM_ASSERTION is removed, use ENABLE_ASSERTIONS instead.)
+endif
+
 include ${MAKE_HELPERS_DIRECTORY}defaults.mk
 
 # Assertions enabled for DEBUG builds by default
-ASM_ASSERTION			:= ${DEBUG}
 ENABLE_ASSERTIONS		:= ${DEBUG}
 ENABLE_PMF			:= ${ENABLE_RUNTIME_INSTRUMENTATION}
 PLAT				:= ${DEFAULT_PLAT}
@@ -440,7 +443,6 @@
 # Build options checks
 ################################################################################
 
-$(eval $(call assert_boolean,ASM_ASSERTION))
 $(eval $(call assert_boolean,COLD_BOOT_SINGLE_CPU))
 $(eval $(call assert_boolean,CREATE_KEYS))
 $(eval $(call assert_boolean,CTX_INCLUDE_AARCH32_REGS))
@@ -480,7 +482,6 @@
 $(eval $(call add_define,ARM_ARCH_MAJOR))
 $(eval $(call add_define,ARM_ARCH_MINOR))
 $(eval $(call add_define,ARM_GIC_ARCH))
-$(eval $(call add_define,ASM_ASSERTION))
 $(eval $(call add_define,COLD_BOOT_SINGLE_CPU))
 $(eval $(call add_define,CTX_INCLUDE_AARCH32_REGS))
 $(eval $(call add_define,CTX_INCLUDE_FPREGS))