arm64: dts: r8a7796: add Sound MIX support

Signed-off-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Signed-off-by: Simon Horman <horms+renesas@verge.net.au>

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

@@ -1197,6 +1197,7 @@ rcar_sound: sound@ec500000 {
 				 <&cpg CPG_MOD 1028>, <&cpg CPG_MOD 1029>,
 				 <&cpg CPG_MOD 1030>, <&cpg CPG_MOD 1031>,
 				 <&cpg CPG_MOD 1020>, <&cpg CPG_MOD 1021>,
+				 <&cpg CPG_MOD 1020>, <&cpg CPG_MOD 1021>,
 				 <&cpg CPG_MOD 1019>, <&cpg CPG_MOD 1018>,
 				 <&audio_clk_a>, <&audio_clk_b>,
 				 <&audio_clk_c>,
@@ -1208,6 +1209,7 @@ rcar_sound: sound@ec500000 {
 				      "src.9", "src.8", "src.7", "src.6",
 				      "src.5", "src.4", "src.3", "src.2",
 				      "src.1", "src.0",
+				      "mix.1", "mix.0",
 				      "ctu.1", "ctu.0",
 				      "dvc.0", "dvc.1",
 				      "clk_a", "clk_b", "clk_c", "clk_i";
@@ -1225,6 +1227,11 @@ dvc1: dvc-1 {
 				};
 			};
 
+			rcar_sound,mix {
+				mix0: mix-0 { };
+				mix1: mix-1 { };
+			};
+
 			rcar_sound,ctu {
 				ctu00: ctu-0 { };
 				ctu01: ctu-1 { };