ath79: dts: Unify naming of gpio-led nodes

In DTS Checklist[1] we're now demanding proper generic node names, as
the name of a node should reflect the function of the device and use
generic name for that[2]. Everybody seems to be copy&pasting from DTS
files available in the repository today, so let's unify that naming
there as well and provide proper examples.

1. https://openwrt.org/submitting-patches#dts_checklist
2. https://github.com/devicetree-org/devicetree-specification/blob/master/source/devicetree-basics.rst#generic-names-recommendation

Signed-off-by: Petr Štetiar <ynezz@true.cz>
[split up, removed entries where it could clash due to ath9k-leds]
Signed-off-by: Christian Lamparter <chunkeey@gmail.com>

target/linux/ath79/dts/ar7161_ubnt_routerstation.dtsi

@@ -25,7 +25,7 @@
 		clock-frequency = <40000000>;
 	};
 
-	gpio-leds {
+	leds {
 		compatible = "gpio-leds";
 
 		rf: rf_green {

target/linux/ath79/dts/ar7240_netgear_wnr612-v2.dtsi

@@ -26,7 +26,7 @@
 		};
 	};
 
-	gpio-leds {
+	leds {
 		compatible = "gpio-leds";
 		power: power {
 			label = "netgear:green:power";

target/linux/ath79/dts/ar9331_pisen_wmm003n.dts

@@ -30,7 +30,7 @@
 		};
 	};
 
-	gpio-leds {
+	leds {
 		compatible = "gpio-leds";
 
 		led_system: system {

target/linux/ath79/dts/ar9331_tplink_tl-wr703n_tl-mr10u.dtsi

@@ -27,7 +27,7 @@
 		};
 	};
 
-	gpio-leds {
+	leds {
 		compatible = "gpio-leds";
 
 		system: system {

target/linux/ath79/dts/ar9331_tplink_tl-wr741nd-v4.dtsi

@@ -37,7 +37,7 @@
 		};
 	};
 
-	gpio-leds {
+	leds {
 		compatible = "gpio-leds";
 		pinctrl-names = "default";
 		pinctrl-0 = <&switch_led_pins>;

target/linux/ath79/dts/ar9342_ubnt_nanostation-ac.dts

@@ -10,7 +10,7 @@
 	compatible = "ubnt,nanostation-ac","ubnt,wa", "qca,ar9342";
 	model = "Ubiquiti Nanostation AC (WA)";
 
-	gpio-leds {
+	leds {
 		compatible = "gpio-leds";
 
 		rssi0 {

target/linux/ath79/dts/ar9342_ubnt_xw.dtsi

@@ -16,7 +16,7 @@
 		led-failsafe = &system;
 	};
 
-	gpio-leds {
+	leds {
 		compatible = "gpio-leds";
 
 		link1 {

target/linux/ath79/dts/qca9557_buffalo_bhr-4grv2.dts

@@ -21,7 +21,7 @@
 		bootargs = "console=ttyS0,115200n8";
 	};
 
-	gpio-leds {
+	leds {
 		compatible = "gpio-leds";
 
 		power: power {