ASoC: Add initial driver for the WM8400 CODEC

The WM8400 is a highly integrated audio CODEC and power management unit
intended for mobile multimedia application.  This driver supports the
primary audio CODEC features, including:

 - 1W speaker driver
 - Fully differential headphone output
 - Up to 4 differential microphone inputs

Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
diff --git a/sound/soc/codecs/Kconfig b/sound/soc/codecs/Kconfig
index a1af311..b6c7f7a 100644
--- a/sound/soc/codecs/Kconfig
+++ b/sound/soc/codecs/Kconfig
@@ -26,6 +26,7 @@
 	select SND_SOC_UDA134X
 	select SND_SOC_UDA1380 if I2C
 	select SND_SOC_WM8350 if MFD_WM8350
+	select SND_SOC_WM8400 if MFD_WM8400
 	select SND_SOC_WM8510 if SND_SOC_I2C_AND_SPI
 	select SND_SOC_WM8580 if I2C
 	select SND_SOC_WM8728 if SND_SOC_I2C_AND_SPI
@@ -110,6 +111,9 @@
 config SND_SOC_WM8350
 	tristate
 
+config SND_SOC_WM8400
+	tristate
+
 config SND_SOC_WM8510
 	tristate