dt-bindings: interrupt-controller: arm,gic-v3: Describe GICv3 optional properties

Describe the optional GICv3 properties:
- clocks
- clock-names
- power-domains
- resets

Signed-off-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>
Reviewed-by: Biju Das <biju.das.jz@bp.renesas.com>
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20210609155108.16590-1-prabhakar.mahadev-lad.rj@bp.renesas.com

Documentation/devicetree/bindings/interrupt-controller/arm,gic-v3.yaml

@@ -145,6 +145,19 @@ properties:
         required:
           - affinity
 
+  clocks:
+    maxItems: 1
+
+  clock-names:
+    items:
+      - const: aclk
+
+  power-domains:
+    maxItems: 1
+
+  resets:
+    maxItems: 1
+
 dependencies:
   mbi-ranges: [ msi-controller ]
   msi-controller: [ mbi-ranges ]