Tegra: support to compile native GICv2 drivers

This patch adds a macro to allow platforms to compile native
GICv2 drivers along with Tegra handlers.

Change-Id: I8281796c09dae5704cff2daab831395d65e261b7
Signed-off-by: Varun Wadekar <vwadekar@nvidia.com>
diff --git a/plat/nvidia/tegra/common/tegra_common.mk b/plat/nvidia/tegra/common/tegra_common.mk
index abb9bb8..6469f75 100644
--- a/plat/nvidia/tegra/common/tegra_common.mk
+++ b/plat/nvidia/tegra/common/tegra_common.mk
@@ -13,7 +13,13 @@
 
 COMMON_DIR		:=	plat/nvidia/tegra/common
 
-BL31_SOURCES		+= 	drivers/console/aarch64/console.S		\
+TEGRA_GICv2_SOURCES	:=	drivers/arm/gic/common/gic_common.c		\
+				drivers/arm/gic/v2/gicv2_main.c			\
+				drivers/arm/gic/v2/gicv2_helpers.c		\
+				plat/common/plat_gicv2.c			\
+				${COMMON_DIR}/tegra_gicv2.c
+
+BL31_SOURCES		+=	drivers/console/aarch64/console.S		\
 				drivers/delay_timer/delay_timer.c		\
 				drivers/ti/uart/aarch64/16550_console.S		\
 				${COMMON_DIR}/aarch64/tegra_helpers.S		\