arm64: dts: renesas: r8a7796: add HDMI sound support

Signed-off-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Tested-by: Nguyen Viet Dung <nv-dung@jinso.co.jp>
Signed-off-by: Simon Horman <horms+renesas@verge.net.au>

arch/arm64/boot/dts/renesas/r8a7796.dtsi

@@ -2009,6 +2009,10 @@ dw_hdmi0_in: endpoint {
 				port@1 {
 					reg = <1>;
 				};
+				port@2 {
+					/* HDMI sound */
+					reg = <2>;
+				};
 			};
 		};