lantiq: add the TDW8980 5GHz led

Still unused, but u-boot doesn't take care of the led, which results in a
permanent switched on 5GHz LED.

Signed-off-by: Mathias Kresin <openwrt@kresin.me>

SVN-Revision: 47915

target/linux/lantiq/dts/TDW8980.dts

@@ -28,4 +28,11 @@
 	ath9k_eep {
 		ath,pci-slot = <0>;
 	};
+
+	gpio-leds {
+		wifi2 {
+			label = "wifi2";
+			gpios = <&gpio 24 1>;
+		};
+	};
 };