arm64: dts: imx8mn-ddr4-evk: Enable GPIO LED

i.MX8MN DDR4 EVK board has a GPIO LED to indicate status,
add support for it.
Signed-off-by: Anson Huang <Anson.Huang@nxp.com>
Signed-off-by: Shawn Guo <shawnguo@kernel.org>

arch/arm64/boot/dts/freescale/imx8mn-ddr4-evk.dts

@@ -15,6 +15,18 @@ chosen {
 		stdout-path = &uart2;
 	};
 
+	gpio-leds {
+		compatible = "gpio-leds";
+		pinctrl-names = "default";
+		pinctrl-0 = <&pinctrl_gpio_led>;
+
+		status {
+			label = "yellow:status";
+			gpios = <&gpio3 16 GPIO_ACTIVE_HIGH>;
+			default-state = "on";
+		};
+	};
+
 	reg_usdhc2_vmmc: regulator-usdhc2 {
 		compatible = "regulator-fixed";
 		pinctrl-names = "default";
@@ -54,6 +66,12 @@ MX8MN_IOMUXC_SAI2_RXC_GPIO4_IO22	0x19
 		>;
 	};
 
+	pinctrl_gpio_led: gpioledgrp {
+		fsl,pins = <
+			MX8MN_IOMUXC_NAND_READY_B_GPIO3_IO16	0x19
+		>;
+	};
+
 	pinctrl_i2c1: i2c1grp {
 		fsl,pins = <
 			MX8MN_IOMUXC_I2C1_SCL_I2C1_SCL		0x400001c3