arm64: dts: marvell: add CP110 ICU SEI subnode

The ICU handles several interrupt groups, each of them being a subpart
of the ICU node.
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Signed-off-by: Gregory CLEMENT <gregory.clement@bootlin.com>

arch/arm64/boot/dts/marvell/armada-cp110.dtsi

@@ -193,6 +193,14 @@ CP110_LABEL(icu_nsr): interrupt-controller@10 {
 				interrupt-controller;
 				msi-parent = <&gicp>;
 			};
+
+			CP110_LABEL(icu_sei): interrupt-controller@50 {
+				compatible = "marvell,cp110-icu-sei";
+				reg = <0x50 0x10>;
+				#interrupt-cells = <2>;
+				interrupt-controller;
+				msi-parent = <&sei>;
+			};
 		};
 
 		CP110_LABEL(rtc): rtc@284000 {