arm64: dts: mediatek: mt8395-radxa-nio-12l: 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 TX 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/mt8395-radxa-nio-12l.dts

@@ -1072,6 +1072,14 @@
 			sound-dai = <&pmic 0>;
 		};
 	};
+
+	hdmi-dai-link {
+		link-name = "ETDM3_OUT_BE";
+
+		codec {
+			sound-dai = <&hdmi 0>;
+		};
+	};
 };
 
 &spi1 {