ARM platforms: Enable SDEI

Support SDEI on ARM platforms using frameworks implemented in earlier
patches by defining and exporting SDEI events: this patch defines the
standard event 0, and a handful of shared and private dynamic events.

Change-Id: I9d3d92a92cff646b8cc55eabda78e140deaa24e1
Signed-off-by: Jeenu Viswambharan <jeenu.viswambharan@arm.com>
diff --git a/plat/arm/common/arm_common.mk b/plat/arm/common/arm_common.mk
index a3cd9d8..17acae5 100644
--- a/plat/arm/common/arm_common.mk
+++ b/plat/arm/common/arm_common.mk
@@ -188,6 +188,10 @@
 BL31_SOURCES		+=	plat/arm/common/aarch64/arm_ehf.c
 endif
 
+ifeq (${SDEI_SUPPORT},1)
+BL31_SOURCES		+=	plat/arm/common/aarch64/arm_sdei.c
+endif
+
 ifneq (${TRUSTED_BOARD_BOOT},0)
 
     # Include common TBB sources