ASoC: rsnd: cleanup regmap table

R-Car Sound is using almost same register mapping on each generation,
therefore we can share it. Here indicates some memo/comments.

SSI/SSIU/SCU have multi channels (SSI0 - SSI9 etc), but ADG is single,
so, we don't need to have multi channel settings for it

	- rsnd_gen_regmap_init(..., 10, ..ADG, ...);
	+ rsnd_gen_regmap_init(...,  1, ..ADG, ...);

Gen4 added new SSI_BUSIF, but it is not used

Gen4 calls rsnd_gen_regmap_init() for SDMC, but the address is calculated
by rsnd_gen4_dma_addr(). It needs physical address, but other info are
not needed. use NULL conf for it.

	- rsnd_gen_regmap_init(..., 10, ..SDMC, conf_sdmc);
	+ rsnd_gen_regmap_init(...,  1, ..SDMC, conf_null);

Gen4 have only SSI0/SSIU0, we don't need to have multi channel settings.

	- rsnd_gen_regmap_init(..., 10, ..SSI, ...);
	+ rsnd_gen_regmap_init(...,  1, ..SSI, ...);

SSI_MODE2 address is different between Gen2/3 and Gen4, but it is not
used on Gen4. Thus we can share same regmap table.

	Gen2/3 : 0x808
	Gen4   : 0xa0c
Signed-off-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Tested-by: Khanh Le <khanh.le.xr@renesas.com>
Link: https://msgid.link/r/871q7obiyt.wl-kuninori.morimoto.gx@renesas.comSigned-off-by: Mark Brown <broonie@kernel.org>

sound/soc/sh/rcar/rsnd.h

@@ -200,7 +200,6 @@ enum rsnd_reg {
 	SSI_SYS_INT_ENABLE5,
 	SSI_SYS_INT_ENABLE6,
 	SSI_SYS_INT_ENABLE7,
-	SSI_BUSIF,
 	HDMI0_SEL,
 	HDMI1_SEL,
 	SSI9_BUSIF0_MODE,