arm64: dts: imx8qxp: Add lsio_mu13 node

lsio_mu13 node is used to communicate with DSP.
Signed-off-by: Daniel Baluta <daniel.baluta@nxp.com>
Signed-off-by: Shawn Guo <shawnguo@kernel.org>

arch/arm64/boot/dts/freescale/imx8qxp.dtsi

@@ -448,6 +448,14 @@ lsio_mu4: mailbox@5d1f0000 {
 			status = "disabled";
 		};
 
+		lsio_mu13: mailbox@5d280000 {
+			compatible = "fsl,imx8qxp-mu", "fsl,imx6sx-mu";
+			reg = <0x5d280000 0x10000>;
+			interrupts = <GIC_SPI 192 IRQ_TYPE_LEVEL_HIGH>;
+			#mbox-cells = <2>;
+			power-domains = <&pd IMX_SC_R_MU_13A>;
+		};
+
 		lsio_gpio0: gpio@5d080000 {
 			compatible = "fsl,imx8qxp-gpio", "fsl,imx35-gpio";
 			reg = <0x5d080000 0x10000>;