mediatek: add common DTS aliases for UniElec U7623 board

 * Use serial0 instead of serial2 for the only serial port
 * Add LED aliases
 * Add ethernet0 alias to inherit ethaddr from U-Boot env

Signed-off-by: Daniel Golle <daniel@makrotopia.org>

target/linux/mediatek/dts/mt7623a-unielec-u7623-02-emmc.dtsi

@@ -11,7 +11,13 @@
 	compatible = "unielec,u7623-02-emmc", "mediatek,mt7623";
 
 	aliases {
-		serial2 = &uart2;
+		serial0 = &uart2;
+		ethernet0 = &gmac0;
+		mmc0 = &mmc0;
+		led-boot = &led3_green;
+		led-failsafe = &led3_green;
+		led-running = &led3_green;
+		led-upgrade = &led3_green;
 	};
 
 	chosen {
@@ -81,7 +87,7 @@
 		pinctrl-names = "default";
 		pinctrl-0 = <&led_pins_unielec>;
 
-		led3 {
+		led3_green: led3 {
 			label = "u7623-01:green:led3";
 			gpios = <&pio 14 GPIO_ACTIVE_LOW>;
 		};