qti: Add RNG driver

This patch adds RNG driver and use it to generate random number for stack
protection.

Change-Id: I73d79e68d08b5aa902dc7fad48e17a03f996178d
Signed-off-by: Saurabh Gorecha <sgorecha@codeaurora.org>
diff --git a/plat/qti/sc7180/platform.mk b/plat/qti/sc7180/platform.mk
index 45e6b33..e551355 100644
--- a/plat/qti/sc7180/platform.mk
+++ b/plat/qti/sc7180/platform.mk
@@ -59,6 +59,7 @@
 				$(QTI_PLAT_PATH)/common/src/qti_syscall.c		\
 				$(QTI_PLAT_PATH)/common/src/qti_topology.c		\
 				$(QTI_PLAT_PATH)/common/src/qti_pm.c			\
+				$(QTI_PLAT_PATH)/common/src/qti_rng.c			\
 				$(QTI_PLAT_PATH)/qtiseclib/src/qtiseclib_cb_interface.c	\