Migrate ARM platforms to use the new GICv3 API

This patch invokes the new function gicv3_rdistif_probe() in the
ARM platform specific gicv3 driver. Since this API modifies the
shared GIC related data structure, it must be invoked coherently
by using the platform specific pwr_domain_on_finish_late hook.

Change-Id: I6efb17d5da61545a1c5a6641b8f58472b31e62a8
Signed-off-by: Madhukar Pappireddy <madhukar.pappireddy@arm.com>