ARM: at91: sama5d3: disable sound by default

Make the sound device in disabled status by default
Signed-off-by: Bo Shen <voice.shen@atmel.com>
Signed-off-by: Nicolas Ferre <nicolas.ferre@atmel.com>

arch/arm/boot/dts/sama5d3xmb.dtsi

@@ -170,5 +170,7 @@ sound {
 
 		atmel,ssc-controller = <&ssc0>;
 		atmel,audio-codec = <&wm8904>;
+
+		status = "disabled";
 	};
 };