ARM platforms: supply per-PE target mask array
ARM platforms: supply per-PE target mask array

Call the GICv2 driver API to initialise per-PE target mask.

Change-Id: Idc7eb0d906a5379f4c05917af05c90613057ab97
Signed-off-by: Jeenu Viswambharan <5b289de972918ffd274229d00560f010009baf9e@arm.com>

lsigithub/arm-trusted-firmware_public,lsigithub/arm-trusted-firmware_public,achingupta/arm-trusted-firmware,achingupta/arm-trusted-firmware