ARM: shmobile: lager: Sound DMA support via DVC on DTS

DMA transfer uses DVC

     DMA               DMApp
[MEM] -> [SRC] -> [DVC] -> [SSIU] -> [SSI]

     DMA               DMApp
[MEM] <- [DVC] <- [SRC] <- [SSIU] <- [SSI]
Signed-off-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Signed-off-by: Simon Horman <horms+renesas@verge.net.au>

arch/arm/boot/dts/r8a7790-lager.dts

@@ -19,6 +19,13 @@
  * This command is required when Playback/Capture
  *
  *	amixer set "LINEOUT Mixer DACL" on
+ *	amixer set "DVC Out" 100%
+ *	amixer set "DVC In" 100%
+ *
+ * You can use Mute
+ *
+ *	amixer set "DVC Out Mute" on
+ *	amixer set "DVC In Mute" on
  */
 
 /dts-v1/;
@@ -569,8 +576,8 @@ &rcar_sound {
 
 	rcar_sound,dai {
 		dai0 {
-			playback = <&ssi0 &src2>;
-			capture  = <&ssi1 &src3>;
+			playback = <&ssi0 &src2 &dvc0>;
+			capture  = <&ssi1 &src3 &dvc1>;
 		};
 	};
 };