ath79: convert Netgear WNDR3700 series to gpio-keys

This patch converts the WNDR3700 to use the interrupt-driven
gpio-keys driver over the polled variant.

Signed-off-by: Christian Lamparter <chunkeey@gmail.com>

target/linux/ath79/dts/ar7161_netgear_wndr3700.dtsi

@@ -81,8 +81,7 @@
 	};
 
 	keys {
-		compatible = "gpio-keys-polled";
+		compatible = "gpio-keys";
-		poll-interval = <100>;
 
 		wps {
 			label = "wps";