ASoC: rsnd: INT_ENABLE is needed only Gen2

INT_ENABLE is needed only Gen2.
rsnd_mod_write() do nothing on Gen1, but it is confusable.
Signed-off-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Signed-off-by: Mark Brown <broonie@linaro.org>

sound/soc/sh/rcar/rsnd.h

@@ -40,7 +40,7 @@ enum rsnd_reg {
 	RSND_REG_SSI_MODE0,
 	RSND_REG_SSI_MODE1,
 	RSND_REG_BUSIF_MODE,
-	RSND_REG_INT_ENABLE,
+	RSND_REG_INT_ENABLE,		/* for Gen2 */
 	RSND_REG_SRC_ADINR,
 
 	/* ADG */

sound/soc/sh/rcar/ssi.c

@@ -457,8 +457,9 @@ static int rsnd_ssi_pio_start(struct rsnd_mod *mod,
 	/* enable PIO IRQ */
 	ssi->cr_etc = UIEN | OIEN | DIEN;
 
-	/* enable PIO interrupt */
-	rsnd_mod_write(&ssi->mod, INT_ENABLE, 0x0f000000);
+	/* 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);