ASoC: rt5677: Add sidetone function

Add sidetone function

Signed-off-by: Anatol Pomozov <anatol.pomozov@gmail.com>
Signed-off-by: Oder Chiou <oder_chiou@realtek.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
diff --git a/sound/soc/codecs/rt5677.h b/sound/soc/codecs/rt5677.h
index b61b72c..1fe8872 100644
--- a/sound/soc/codecs/rt5677.h
+++ b/sound/soc/codecs/rt5677.h
@@ -382,6 +382,10 @@
 #define RT5677_ST_SEL_SFT			9
 #define RT5677_ST_EN				(0x1 << 6)
 #define RT5677_ST_EN_SFT			6
+#define RT5677_ST_GAIN				(0x1 << 5)
+#define RT5677_ST_GAIN_SFT			5
+#define RT5677_ST_VOL_MASK			(0x1f << 0)
+#define RT5677_ST_VOL_SFT			0
 
 /* Analog DAC1/2/3 Source Control (0x15) */
 #define RT5677_ANA_DAC3_SRC_SEL_MASK		(0x3 << 4)