arm64: dts: rockchip: Describe RK3328 GPIO_MUTE users

Add explicit properties to describe existing boards' GPIO_MUTE usage
for the analog codec.
Signed-off-by: Robin Murphy <robin.murphy@arm.com>
Link: https://lore.kernel.org/r/53637c0359ad9473dc1391a8428ba21017ec467e.1581376744.git.robin.murphy@arm.comSigned-off-by: Heiko Stuebner <heiko@sntech.de>

arch/arm64/boot/dts/rockchip/rk3328-a1.dts

@@ -60,6 +60,7 @@ &analog_sound {
 };
 
 &codec {
+	mute-gpios = <&grf_gpio 0 GPIO_ACTIVE_LOW>;
 	status = "okay";
 };
 

arch/arm64/boot/dts/rockchip/rk3328-rock64.dts

@@ -104,6 +104,7 @@ dit_p0_0: endpoint {
 };
 
 &codec {
+	mute-gpios = <&grf_gpio 0 GPIO_ACTIVE_LOW>;
 	status = "okay";
 
 	port@0 {