arm64: dts: rockchip: Add sound-dai-cells for RK3368

Add the missing #sound-dai-cells for RK3368's I2S and S/PDIF controllers.

Fixes: f7d89dfe ("arm64: dts: rockchip: add i2s nodes support for RK3368 SoCs")
Fixes: 0328d68e ("arm64: dts: rockchip: add rk3368 spdif node")
Signed-off-by: Alex Bee <knaerzche@gmail.com>
Link: https://lore.kernel.org/r/20240623090116.670607-4-knaerzche@gmail.comSigned-off-by: Heiko Stuebner <heiko@sntech.de>

arch/arm64/boot/dts/rockchip/rk3368.dtsi

@@ -793,6 +793,7 @@ spdif: spdif@ff880000 {
 		dma-names = "tx";
 		pinctrl-names = "default";
 		pinctrl-0 = <&spdif_tx>;
+		#sound-dai-cells = <0>;
 		status = "disabled";
 	};
 
@@ -804,6 +805,7 @@ i2s_2ch: i2s-2ch@ff890000 {
 		clocks = <&cru SCLK_I2S_2CH>, <&cru HCLK_I2S_2CH>;
 		dmas = <&dmac_bus 6>, <&dmac_bus 7>;
 		dma-names = "tx", "rx";
+		#sound-dai-cells = <0>;
 		status = "disabled";
 	};
 
@@ -817,6 +819,7 @@ i2s_8ch: i2s-8ch@ff898000 {
 		dma-names = "tx", "rx";
 		pinctrl-names = "default";
 		pinctrl-0 = <&i2s_8ch_bus>;
+		#sound-dai-cells = <0>;
 		status = "disabled";
 	};