arm64: dts: imx: align LED node names with dtschema

The node names should be generic and DT schema expects certain pattern:

  freescale/imx8mm-emcon-avari.dtb: leds: 'green', 'red' do not match any of the regexes: '(^led-[0-9a-f]$|led)', 'pinctrl-[0-9]+'
Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Signed-off-by: Shawn Guo <shawnguo@kernel.org>

arch/arm64/boot/dts/freescale/imx8mm-emcon.dtsi

@@ -18,14 +18,14 @@ som_leds: leds {
 		pinctrl-names = "default";
 		pinctrl-0 = <&pinctrl_gpio_led>;
 
-		green {
+		led-green {
 			label = "som:green";
 			gpios = <&gpio3 4 GPIO_ACTIVE_HIGH>;
 			default-state = "on";
 			linux,default-trigger = "heartbeat";
 		};
 
-		red {
+		led-red {
 			label = "som:red";
 			gpios = <&gpio5 10 GPIO_ACTIVE_HIGH>;
 			default-state = "off";

arch/arm64/boot/dts/freescale/imx8mq-librem5-devkit.dts

@@ -64,7 +64,7 @@ button-3 {
 	leds {
 		compatible = "pwm-leds";
 
-		led1 {
+		led-1 {
 			function = LED_FUNCTION_STATUS;
 			color = <LED_COLOR_ID_RED>;
 			max-brightness = <248>;