GICv3: Add ITS entry to THUNDER dts

The PCIe host controller uses MSIs provided by GICv3 ITS. Enable it on
Thunder SoCs by adding an entry to DT.
Signed-off-by: Tirumalesh Chalamarla <tchalamarla@cavium.com>
Acked-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Kevin Hilman <khilman@linaro.org>

arch/arm64/boot/dts/cavium/thunder-88xx.dtsi

@@ -376,10 +376,19 @@ refclk50mhz: refclk50mhz {
 		gic0: interrupt-controller@8010,00000000 {
 			compatible = "arm,gic-v3";
 			#interrupt-cells = <3>;
+			#address-cells = <2>;
+			#size-cells = <2>;
+			ranges;
 			interrupt-controller;
 			reg = <0x8010 0x00000000 0x0 0x010000>, /* GICD */
 			      <0x8010 0x80000000 0x0 0x600000>; /* GICR */
 			interrupts = <1 9 0xf04>;
+
+			its: gic-its@8010,00020000 {
+				compatible = "arm,gic-v3-its";
+				msi-controller;
+				reg = <0x8010 0x20000 0x0 0x200000>;
+			};
 		};
 
 		uaa0: serial@87e0,24000000 {