arm64: dts: r8a77970: Add INTC-EX device node

Add a device node for the Interrupt Controller for External Devices
(INTC-EX) on R-Car V3M, which serves external IRQ pins IRQ[0-5].
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Simon Horman <horms+renesas@verge.net.au>

arch/arm64/boot/dts/renesas/r8a77970.dtsi

@@ -124,6 +124,22 @@ sysc: system-controller@e6180000 {
 			#power-domain-cells = <1>;
 		};
 
+		intc_ex: interrupt-controller@e61c0000 {
+			compatible = "renesas,intc-ex-r8a77970", "renesas,irqc";
+			#interrupt-cells = <2>;
+			interrupt-controller;
+			reg = <0 0xe61c0000 0 0x200>;
+			interrupts = <GIC_SPI 0 IRQ_TYPE_LEVEL_HIGH
+				      GIC_SPI 1 IRQ_TYPE_LEVEL_HIGH
+				      GIC_SPI 2 IRQ_TYPE_LEVEL_HIGH
+				      GIC_SPI 3 IRQ_TYPE_LEVEL_HIGH
+				      GIC_SPI 18 IRQ_TYPE_LEVEL_HIGH
+				      GIC_SPI 161 IRQ_TYPE_LEVEL_HIGH>;
+			clocks = <&cpg CPG_MOD 407>;
+			power-domains = <&sysc 32>;
+			resets = <&cpg 407>;
+		};
+
 		prr: chipid@fff00044 {
 			compatible = "renesas,prr";
 			reg = <0 0xfff00044 0 4>;