ASoC: rt5640: add Mono ADC Capture Switch control

Mono ADC Capture Switch control is missing in the driver. So, add it.

Signed-off-by: Bard Liao <bardliao@realtek.com>
Tested-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
diff --git a/sound/soc/codecs/rt5640.h b/sound/soc/codecs/rt5640.h
index 22c017c..b8a81173 100644
--- a/sound/soc/codecs/rt5640.h
+++ b/sound/soc/codecs/rt5640.h
@@ -1971,6 +1971,10 @@
 #define RT5640_ZCD_HP_EN			(0x1 << 15)
 
 /* General Control 1 (0xfa) */
+#define RT5640_M_MONO_ADC_L			(0x1 << 13)
+#define RT5640_M_MONO_ADC_L_SFT			13
+#define RT5640_M_MONO_ADC_R			(0x1 << 12)
+#define RT5640_M_MONO_ADC_R_SFT			12
 #define RT5640_MCLK_DET				(0x1 << 11)
 
 /* Codec Private Register definition */