This patch checks that the pointers to BL3-3 and BL3-2 ep_info
structs are valid before accessing them. Add some INFO prints
in the BL3-1 setup path for early debugging purposes.

Change-Id: I62b23fa870f1b2fb783c8de69aab819f1749d15a
Signed-off-by: Varun Wadekar <vwadekar@nvidia.com>