plat/arm/gicv3: add support for probing multiple GIC Redistributor frames

ARM platform can have a non-contiguous GICR frames. For instance, a
multi socket platform can have two or more GIC Redistributor frames
which are 4TB apart. Hence it is necessary for the `gicv3_rdistif_probe`
function to probe all the GICR frames available in the platform.

Introduce `plat_arm_override_gicr_frames` function which platforms can
use to override the default gicr_frames which holds the GICR base
address of the primary cpu.

Change-Id: I1f537b0d871a679cb256092944737f2e55ab866e
Signed-off-by: Vijayenthiran Subramaniam <vijayenthiran.subramaniam@arm.com>
diff --git a/include/plat/arm/common/plat_arm.h b/include/plat/arm/common/plat_arm.h
index 07a46c5..c00a041 100644
--- a/include/plat/arm/common/plat_arm.h
+++ b/include/plat/arm/common/plat_arm.h
@@ -254,6 +254,11 @@
 int plat_arm_bl1_fwu_needed(void);
 __dead2 void plat_arm_error_handler(int err);
 
+/*
+ * Optional function in ARM standard platforms
+ */
+void plat_arm_override_gicr_frames(const uintptr_t *plat_gicr_frames);
+
 #if ARM_PLAT_MT
 unsigned int plat_arm_get_cpu_pe_count(u_register_t mpidr);
 #endif