arm64: dts: imx8mp: add ddr pmu device node

Add ddr pmu device node for i.MX8MP.
Signed-off-by: Joakim Zhang <qiangqing.zhang@nxp.com>
Signed-off-by: Shawn Guo <shawnguo@kernel.org>

arch/arm64/boot/dts/freescale/imx8mp.dtsi

@@ -744,5 +744,11 @@ gic: interrupt-controller@38800000 {
 			interrupts = <GIC_PPI 9 IRQ_TYPE_LEVEL_HIGH>;
 			interrupt-parent = <&gic>;
 		};
+
+		ddr-pmu@3d800000 {
+			compatible = "fsl,imx8mp-ddr-pmu", "fsl,imx8m-ddr-pmu";
+			reg = <0x3d800000 0x400000>;
+			interrupts = <GIC_SPI 98 IRQ_TYPE_LEVEL_HIGH>;
+		};
 	};
 };