ASoC: add RT5670 CODEC driver

This patch adds a minimum support of Realtek ALC5670 codec.

Signed-off-by: Bard Liao <bardliao@realtek.com>
Signed-off-by: Mark Brown <broonie@linaro.org>
diff --git a/sound/soc/codecs/Kconfig b/sound/soc/codecs/Kconfig
index 9d88845..f31b132 100644
--- a/sound/soc/codecs/Kconfig
+++ b/sound/soc/codecs/Kconfig
@@ -78,6 +78,7 @@
 	select SND_SOC_RT5640 if I2C
 	select SND_SOC_RT5645 if I2C
 	select SND_SOC_RT5651 if I2C
+	select SND_SOC_RT5670 if I2C
 	select SND_SOC_RT5677 if I2C
 	select SND_SOC_SGTL5000 if I2C
 	select SND_SOC_SI476X if MFD_SI476X_CORE
@@ -445,10 +446,12 @@
 	default y if SND_SOC_RT5640=y
 	default y if SND_SOC_RT5645=y
 	default y if SND_SOC_RT5651=y
+	default y if SND_SOC_RT5670=y
 	default y if SND_SOC_RT5677=y
 	default m if SND_SOC_RT5640=m
 	default m if SND_SOC_RT5645=m
 	default m if SND_SOC_RT5651=m
+	default m if SND_SOC_RT5670=m
 	default m if SND_SOC_RT5677=m
 
 config SND_SOC_RT5631
@@ -463,6 +466,9 @@
 config SND_SOC_RT5651
 	tristate
 
+config SND_SOC_RT5670
+	tristate
+
 config SND_SOC_RT5677
 	tristate