arm64: dts: imx8qm-mek: enable 8qm lpuart2 and lpuart3

Enable uart2 and uart3 for imx8qm-mek board.
Signed-off-by: Frank Li <Frank.Li@nxp.com>
Signed-off-by: Shawn Guo <shawnguo@kernel.org>

arch/arm64/boot/dts/freescale/imx8qm-mek.dts

@@ -47,6 +47,18 @@ &lpuart0 {
 	status = "okay";
 };
 
+&lpuart2 {
+	pinctrl-names = "default";
+	pinctrl-0 = <&pinctrl_lpuart2>;
+	status = "okay";
+};
+
+&lpuart3 {
+	pinctrl-names = "default";
+	pinctrl-0 = <&pinctrl_lpuart3>;
+	status = "okay";
+};
+
 &fec1 {
 	pinctrl-names = "default";
 	pinctrl-0 = <&pinctrl_fec1>;
@@ -118,6 +130,20 @@ IMX8QM_UART0_TX_DMA_UART0_TX				0x06000020
 		>;
 	};
 
+	pinctrl_lpuart2: lpuart2grp {
+		fsl,pins = <
+			IMX8QM_UART0_RTS_B_DMA_UART2_RX				0x06000020
+			IMX8QM_UART0_CTS_B_DMA_UART2_TX				0x06000020
+		>;
+	};
+
+	pinctrl_lpuart3: lpuart3grp {
+		fsl,pins = <
+			IMX8QM_M41_GPIO0_00_DMA_UART3_RX			0x06000020
+			IMX8QM_M41_GPIO0_01_DMA_UART3_TX			0x06000020
+		>;
+	};
+
 	pinctrl_usdhc1: usdhc1grp {
 		fsl,pins = <
 			IMX8QM_EMMC0_CLK_CONN_EMMC0_CLK				0x06000041