corstone700: adding support for stack protector for the FVP

Adding support for generating a semi-random number required for
enabling building TF-A with stack protector support.
TF-A for corstone-700 may now be built using ENABLE_STACK_PROTECTOR=all

Change-Id: I03e1be1a8d4e4a822cf286f3b9ad4da4337ca765
Signed-off-by: Abdellatif El Khlifi <abdellatif.elkhlifi@arm.com>
2 files changed