arm64: dts: renesas: r8a779a0: Add INTC-EX device node

Populate the device node for the Interrupt Controller for External
Devices (INTC-EX) on R-Car V3U, which serves external IRQ pins IRQ[0-5].
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Tested-by: Kieran Bingham <kieran.bingham+renesas@ideasonboard.com>
Link: https://lore.kernel.org/r/4e2297e1066df483c0434df487df5b79e76b75b8.1624460378.git.geert+renesas@glider.be

arch/arm64/boot/dts/renesas/r8a779a0.dtsi

@@ -340,6 +340,21 @@ tsc: thermal@e6190000 {
 			#thermal-sensor-cells = <1>;
 		};
 
+		intc_ex: interrupt-controller@e61c0000 {
+			compatible = "renesas,intc-ex-r8a779a0", "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 4 IRQ_TYPE_LEVEL_HIGH>,
+				     <GIC_SPI 5 IRQ_TYPE_LEVEL_HIGH>;
+			clocks = <&cpg CPG_CORE R8A779A0_CLK_CP>;
+			power-domains = <&sysc R8A779A0_PD_ALWAYS_ON>;
+		};
+
 		tmu0: timer@e61e0000 {
 			compatible = "renesas,tmu-r8a779a0", "renesas,tmu";
 			reg = <0 0xe61e0000 0 0x30>;