feat(spmc): enable building of the SPMC at EL3

Introduce build flag for enabling the secure partition
manager core, SPMC_AT_EL3. When enabled, the SPMC module
will be included into the BL31 image. By default the
flag is disabled.

Signed-off-by: Marc Bonnici <marc.bonnici@arm.com>
Change-Id: I5ea1b953e5880a07ffc91c4dea876a375850cf2a
5 files changed