arm64: dts: imx8ulp: add mailbox node

Add Sentinel Message Unit(MU), Generic MU nodes.
Signed-off-by: Peng Fan <peng.fan@nxp.com>
Signed-off-by: Shawn Guo <shawnguo@kernel.org>

arch/arm64/boot/dts/freescale/imx8ulp.dtsi

@@ -152,6 +152,13 @@ soc: soc@0 {
 		#size-cells = <1>;
 		ranges = <0x0 0x0 0x0 0x40000000>;
 
+		s4muap: mailbox@27020000 {
+			compatible = "fsl,imx8ulp-mu-s4";
+			reg = <0x27020000 0x10000>;
+			interrupts = <GIC_SPI 79 IRQ_TYPE_LEVEL_HIGH>;
+			#mbox-cells = <2>;
+		};
+
 		per_bridge3: bus@29000000 {
 			compatible = "simple-bus";
 			reg = <0x29000000 0x800000>;
@@ -159,6 +166,23 @@ per_bridge3: bus@29000000 {
 			#size-cells = <1>;
 			ranges;
 
+			mu: mailbox@29220000 {
+				compatible = "fsl,imx8ulp-mu";
+				reg = <0x29220000 0x10000>;
+				interrupts = <GIC_SPI 73 IRQ_TYPE_LEVEL_HIGH>;
+				#mbox-cells = <2>;
+				status = "disabled";
+			};
+
+			mu3: mailbox@29230000 {
+				compatible = "fsl,imx8ulp-mu";
+				reg = <0x29230000 0x10000>;
+				interrupts = <GIC_SPI 75 IRQ_TYPE_LEVEL_HIGH>;
+				clocks = <&pcc3 IMX8ULP_CLK_MU3_A>;
+				#mbox-cells = <2>;
+				status = "disabled";
+			};
+
 			wdog3: watchdog@292a0000 {
 				compatible = "fsl,imx8ulp-wdt", "fsl,imx7ulp-wdt";
 				reg = <0x292a0000 0x10000>;