ASoC: rsnd: add rsnd_io_to_rdai()

Current rsnd driver request rdai in everywhere, but each mod should
reach to rdai by itself. this patch adds missing rsnd_io_to_rdai().

io   = rsnd_mod_to_io(mod);
rdai = rsnd_io_to_rdai(io);

Signed-off-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
diff --git a/sound/soc/sh/rcar/rsnd.h b/sound/soc/sh/rcar/rsnd.h
index ad76870..0b55182 100644
--- a/sound/soc/sh/rcar/rsnd.h
+++ b/sound/soc/sh/rcar/rsnd.h
@@ -282,6 +282,7 @@
 	struct snd_pcm_substream *substream;
 	struct rsnd_mod *mod[RSND_MOD_MAX];
 	struct rsnd_dai_path_info *info; /* rcar_snd.h */
+	struct rsnd_dai *rdai;
 	int byte_pos;
 	int period_pos;
 	int byte_per_period;
@@ -290,6 +291,7 @@
 #define rsnd_io_to_mod_ssi(io)	((io)->mod[RSND_MOD_SSI])
 #define rsnd_io_to_mod_src(io)	((io)->mod[RSND_MOD_SRC])
 #define rsnd_io_to_mod_dvc(io)	((io)->mod[RSND_MOD_DVC])
+#define rsnd_io_to_rdai(io)	((io)->rdai)
 #define rsnd_io_to_runtime(io) ((io)->substream ? \
 				(io)->substream->runtime : NULL)