ASoC: rsnd: extracts Gen1/Gen2 common parts

Renesas sound IP Gen1/Gen2 are similar, but different.
This patch extracts Gen1/Gen2 common and dependency parts,
and create Gen1/Gen2 ops to control it.

According to this structure, SSIU setup which
has been implemented on ssi.c can be moved to scu.c
(SRU/SSIU/SCU should be implemented on scu.c)
Signed-off-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Signed-off-by: Mark Brown <broonie@linaro.org>

sound/soc/sh/rcar/rsnd.h

@@ -48,7 +48,7 @@ enum rsnd_reg {
 	RSND_REG_SRC_IFSCR,
 	RSND_REG_SRC_IFSVR,
 	RSND_REG_SRC_SRCCR,
-	RSND_REG_SRC_MNFSR,
+	RSND_REG_SRC_MNFSR,		/* for Gen1 */
 
 	/* ADG */
 	RSND_REG_BRRA,

sound/soc/sh/rcar/ssi.c

@@ -363,16 +363,11 @@ static int rsnd_ssi_pio_start(struct rsnd_mod *mod,
 			      struct rsnd_dai *rdai,
 			      struct rsnd_dai_stream *io)
 {
-	struct rsnd_priv *priv = rsnd_mod_to_priv(mod);
 	struct rsnd_ssi *ssi = rsnd_mod_to_ssi(mod);
 
 	/* enable PIO IRQ */
 	ssi->cr_etc = UIEN | OIEN | DIEN;
 
-	/* enable PIO interrupt if gen2 */
-	if (rsnd_is_gen2(priv))
-		rsnd_mod_write(&ssi->mod, INT_ENABLE, 0x0f000000);
-
 	rsnd_ssi_hw_start(ssi, rdai, io);
 
 	return 0;