ARM: dts: meson: align LED node names with dtschema

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

meson8-minix-neo-x8.dtb: gpio-leds: 'blue' does not match any of the regexes: '(^led-[0-9a-f]$|led)', 'pinctrl-[0-9]+'

Signed-off-by: Krzysztof Kozlowski <[e-mail]>
Reviewed-by: Neil Armstrong <[e-mail]>
Reviewed-by: Martin Blumenstingl <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]
Signed-off-by: Neil Armstrong <[e-mail]>

arch/arm/boot/dts/meson8-minix-neo-x8.dts

···
 	gpio-leds {
 		compatible = "gpio-leds";
 
-		blue {
+		led-blue {
 			label = "x8:blue:power";
 			gpios = <&gpio_ao GPIO_TEST_N GPIO_ACTIVE_HIGH>;
 		};

arch/arm/boot/dts/meson8b-ec100.dts

···
 	leds {
 		compatible = "gpio-leds";
 
-		power {
+		led-power {
 			label = "ec100:red:power";
 			/*
 			 * Needs to go LOW (together with the poweroff GPIO)

arch/arm/boot/dts/meson8b-odroidc1.dts

···
 
 	leds {
 		compatible = "gpio-leds";
-		blue {
+		led-blue {
 			label = "c1:blue:alive";
 			gpios = <&gpio_ao GPIOAO_13 GPIO_ACTIVE_LOW>;
 			linux,default-trigger = "heartbeat";