Arm platforms: Remove common RAS configuration source

The file arm_ras.c intended to provide common platform-specific RAS
configuration for Arm platforms. Because this file has symbol
definitions, it's proving difficult to provide a common definition.

This patch therefore renames and makes the file specific to FVP. Other
platforms shall provide their own configuration in similar fashion.

Change-Id: I766fd238946e3e49cdb659680e1b45f41b237901
Signed-off-by: Jeenu Viswambharan <jeenu.viswambharan@arm.com>
diff --git a/plat/arm/board/fvp/platform.mk b/plat/arm/board/fvp/platform.mk
index 3a28733..ed41d4c 100644
--- a/plat/arm/board/fvp/platform.mk
+++ b/plat/arm/board/fvp/platform.mk
@@ -216,6 +216,10 @@
 				lib/cpus/aarch64/cpuamu_helpers.S
 endif
 
+ifeq (${RAS_EXTENSION},1)
+BL31_SOURCES		+=	plat/arm/board/fvp/aarch64/fvp_ras.c
+endif
+
 ifneq (${ENABLE_STACK_PROTECTOR},0)
 PLAT_BL_COMMON_SOURCES	+=	plat/arm/board/fvp/fvp_stack_protector.c
 endif