TF-A GICv3 driver: Add extended PPI and SPI range

This patch provides support for GICv3.1 extended PPI and SPI
range. The option is enabled by setting to 1 and passing
`GIC_EXT_INTID` build flag to gicv3.mk makefile.
This option defaults to 0 with no extended range support.

Change-Id: I7d09086fe22ea531c5df51a8a1efd8928458d394
Signed-off-by: Alexei Fedorov <Alexei.Fedorov@arm.com>
8 files changed