TF-A GICv3 driver: Separate GICD and GICR accessor functions

This patch provides separation of GICD, GICR accessor
functions and adds new macros for GICv3 registers access
as a preparation for GICv3.1 and GICv4 support.
NOTE: Platforms need to modify to include both
'gicdv3_helpers.c' and 'gicrv3_helpers.c' instead of the
single helper file previously.

Change-Id: I1641bd6d217d6eb7d1228be3c4177b2d556da60a
Signed-off-by: Alexei Fedorov <Alexei.Fedorov@arm.com>
diff --git a/plat/xilinx/versal/platform.mk b/plat/xilinx/versal/platform.mk
index 1e231cc..5d7fd69 100644
--- a/plat/xilinx/versal/platform.mk
+++ b/plat/xilinx/versal/platform.mk
@@ -52,6 +52,8 @@
 				drivers/arm/gic/v3/gic500.c			\
 				drivers/arm/gic/v3/gicv3_main.c			\
 				drivers/arm/gic/v3/gicv3_helpers.c		\
+				drivers/arm/gic/v3/gicdv3_helpers.c	\
+				drivers/arm/gic/v3/gicrv3_helpers.c	\
 				drivers/arm/pl011/aarch64/pl011_console.S	\
 				plat/common/aarch64/crash_console_helpers.S	\
 				plat/arm/common/arm_cci.c			\