Configs for ENABLE_PIE=1 testing

Adding configs to test ENABLE_PIE=1 for BL31 with RESET_TO_BL31=0, TSP,
and BL2_AT_EL3.

Signed-off-by: Lauren Wehrmeister <lauren.wehrmeister@arm.com>
Change-Id: I82065281605dd441345b798948fcd6a1afa2103d
6 files changed