ramips: remove Planex CS-QR10 sound device tree node

The comptible string is neither added by any LEDE patch nor exists in
in the kernel. Drop the sound node which was obviously added
accidentally with 9195d8da ("ramips: DTS rework").

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

target/linux/ramips/dts/CS-QR10.dts

@@ -8,17 +8,6 @@
 	compatible = "ralink,mt7620a-soc";
 	model = "Planex CS-QR10";
 
-	sound {
-		compatible = "mediatek,mt7620-audio-wm8960";
-		model = "mt7620-wm8960";
-		i2s-controller = <&i2s>;
-		audio-routing =
-			"Ext Spk", "SPK_LP",
-			"Ext Spk", "SPK_LN",
-			"Ext Spk", "SPK_RP",
-			"Ext Spk", "SPK_RN";
-	};
-
 	gpio-leds {
 		compatible = "gpio-leds";