arm64: dts: mediatek: mt8390-genio-common: Add HDMI sound output support

Add in the sound node a new dai-link for ETDM3_OUT_BE to add the sound
output support through the HDMI connector.

Signed-off-by: Louis-Alexis Eyraud <louisalexis.eyraud@collabora.com>
Signed-off-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>

Author: laeyraud

arch/arm64/boot/dts/mediatek/mt8390-genio-common.dtsi

@@ -1344,6 +1344,15 @@
 			sound-dai = <&dmic_codec>;
 		};
 	};
+
+	dai-link-2 {
+		link-name = "ETDM3_OUT_BE";
+
+		codec {
+			sound-dai = <&hdmi 0>;
+		};
+	};
+
 };
 
 &spi2 {