feat(fvp): enable test to access el3 memory

With newly introduced test to perform invalid accesses requires platform
to provide test memory addresses. This patch provides EL3 memory access
address for FVP platform.
The invalid_access test will try to access el3 owned memory from
tftf(ns-el2).

Signed-off-by: Manish Pandey <manish.pandey2@arm.com>
Change-Id: I9c9493f1b33bdd91d8d4140cf9e96b2d9007fbe2
2 files changed