ath79: ZTE MF286[,A,R]: fix WLAN LED mapping

The default configuration of pinctrl for GPIO19 set by U-boot was not a
GPIO, but an alternate function, which prevented the GPIO hog from
working. Set GPIO19 into GPIO mode to allow the hog to work, then the
ath10k LED output can control the state of actual LED properly.

Link: <openwrt#9941>
Signed-off-by: Lech Perczak <lech.perczak@gmail.com>

target/linux/ath79/dts/qca9563_zte_mf286.dtsi

@@ -18,6 +18,8 @@
 
 	leds {
 		compatible = "gpio-leds";
+		pinctrl-names = "default";
+		pinctrl-0 = <&enable_wlan_led_gpio>;
 
 		/* Hidden SMD LED below signal strength LEDs.
 		 * Visible through slits underside of the case,
@@ -137,6 +139,12 @@
 	};
 };
 
+&pinmux {
+	enable_wlan_led_gpio: pinmux_wlan_led_gpio {
+		pinctrl-single,bits = <0x10 0x0 0xff000000>;
+	};
+};
+
 &wmac {
 	status = "okay";
 };