ASoC: Add WM8993 CODEC driver

The WM8993 is a highly integrated ultra-low power hi-fi CODEC designed
for portable devices such as multimedia phones.

Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
diff --git a/sound/soc/codecs/Kconfig b/sound/soc/codecs/Kconfig
index 68ea5b6..b674d3a 100644
--- a/sound/soc/codecs/Kconfig
+++ b/sound/soc/codecs/Kconfig
@@ -44,6 +44,7 @@
 	select SND_SOC_WM8971 if I2C
 	select SND_SOC_WM8988 if SND_SOC_I2C_AND_SPI
 	select SND_SOC_WM8990 if I2C
+	select SND_SOC_WM8993 if I2C
 	select SND_SOC_WM9081 if I2C
 	select SND_SOC_WM9705 if SND_SOC_AC97_BUS
 	select SND_SOC_WM9712 if SND_SOC_AC97_BUS
@@ -173,6 +174,9 @@
 config SND_SOC_WM8990
 	tristate
 
+config SND_SOC_WM8993
+	tristate
+
 config SND_SOC_WM9081
 	tristate