rockchip: Add support for the stack protector

It uses the system timer as "entropy" source in the same
way as QEMU, layerscape and others.

Change-Id: Icda17b78e85255bea96109ca2ee0e091187d62ac
Signed-off-by: Christoph Müllner <christophm30@gmail.com>
diff --git a/plat/rockchip/rk3368/platform.mk b/plat/rockchip/rk3368/platform.mk
index cb0cb89..e787293 100644
--- a/plat/rockchip/rk3368/platform.mk
+++ b/plat/rockchip/rk3368/platform.mk
@@ -33,6 +33,10 @@
 				plat/common/aarch64/crash_console_helpers.S	\
 				plat/common/plat_psci_common.c
 
+ifneq (${ENABLE_STACK_PROTECTOR},0)
+PLAT_BL_COMMON_SOURCES	+=	${RK_PLAT_COMMON}/rockchip_stack_protector.c
+endif
+
 BL31_SOURCES		+=	${RK_GIC_SOURCES}				\
 				drivers/arm/cci/cci.c				\
 				drivers/ti/uart/aarch64/16550_console.S		\