arm64: dts: imx8mp-evk: Add GPIO LED support

i.MX8MP EVK board has a GPIO LED to indicate status, add support for it.
Signed-off-by: NAnson Huang <Anson.Huang@nxp.com>
Signed-off-by: NShawn Guo <shawnguo@kernel.org>

arch/arm64/boot/dts/freescale/imx8mp-evk.dts

@@ -15,6 +15,18 @@
 		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";
+		};
+	};
+
 	memory@40000000 {
 		device_type = "memory";
 		reg = <0x0 0x40000000 0 0xc0000000>,
@@ -120,6 +132,12 @@
 		>;
 	};
 
+	pinctrl_gpio_led: gpioledgrp {
+		fsl,pins = <
+			MX8MP_IOMUXC_NAND_READY_B__GPIO3_IO16	0x19
+		>;
+	};
+
 	pinctrl_reg_usdhc2_vmmc: regusdhc2vmmc {
 		fsl,pins = <
 			MX8MP_IOMUXC_SD2_RESET_B__GPIO2_IO19	0x41