drivers: gicv3: Introduce aff0 matching config for rdist

Some platforms only use aff0 to match mpdir and GICR.aff. Introduce
GIC_V3_RDIST_MATCHING_AFF0_ONLY to set the matching method only using
aff0. With this config enabled, the matching function will find the
target redistributor by comparing the aff0 only.

Signed-off-by: Jaxson Han <jaxson.han@arm.com>