ASoC: rsnd: ctu: add rsnd_mix_activation()

Based on datasheet

Signed-off-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

sound/soc/sh/rcar/gen.c

@@ -260,6 +260,7 @@ static int rsnd_gen2_probe(struct rsnd_priv *priv)
 		RSND_GEN_M_REG(SRC_SRCCR,	0x224,	0x40),
 		RSND_GEN_M_REG(SRC_BSDSR,	0x22c,	0x40),
 		RSND_GEN_M_REG(SRC_BSISR,	0x238,	0x40),
+		RSND_GEN_M_REG(CTU_SWRSR,	0x500,	0x100),
 		RSND_GEN_M_REG(CTU_CTUIR,	0x504,	0x100),
 		RSND_GEN_M_REG(CTU_ADINR,	0x508,	0x100),
 		RSND_GEN_M_REG(MIX_SWRSR,	0xd00,	0x40),