The TZRAM memory loses its state during "System Suspend". This patch
check if TZRAM base address contains valid data, to decide if the system
is exiting from "System Suspend". To enable TZDRAM encryption, the Memory
Controller's TZDRAM base/size registers would be populated by the BPMP
when the system "wakes up".

Change-Id: I5fc8ba1ae3bce12f0ece493f6f9f5f4d92a46344
Signed-off-by: Varun Wadekar <vwadekar@nvidia.com>