ARM Platforms: Support RAS

  - Assign 0x10 for RAS exceptions on ARM platforms, and install
    EHF priority descriptor.

  - Call the common RAS initialisation from ARM BL31 setup.

  - Add empty definitions for platform error records and RAS interrupts.

Change-Id: I0675f299b7840be4c83a9c7a81073a95c605dc90
Signed-off-by: Jeenu Viswambharan <jeenu.viswambharan@arm.com>
diff --git a/include/plat/arm/common/arm_def.h b/include/plat/arm/common/arm_def.h
index 95e986b..d10afae 100644
--- a/include/plat/arm/common/arm_def.h
+++ b/include/plat/arm/common/arm_def.h
@@ -483,6 +483,7 @@
 #define PLAT_PERCPU_BAKERY_LOCK_SIZE		(1 * CACHE_WRITEBACK_GRANULE)
 
 /* Priority levels for ARM platforms */
+#define PLAT_RAS_PRI			0x10
 #define PLAT_SDEI_CRITICAL_PRI		0x60
 #define PLAT_SDEI_NORMAL_PRI		0x70