mfd: Make WM8400 depend on I2C until SPI is submitted

Otherwise we could build in WM8400 but not I2C.
Signed-off-by: NMark Brown <broonie@opensource.wolfsonmicro.com>
Signed-off-by: NSamuel Ortiz <sameo@openedhand.com>

drivers/mfd/Kconfig

@@ -116,6 +116,7 @@ config PMIC_DA903X
 
 config MFD_WM8400
 	tristate "Support Wolfson Microelectronics WM8400"
+	depends on I2C
 	help
 	  Support for the Wolfson Microelecronics WM8400 PMIC and audio
 	  CODEC.  This driver adds provides common support for accessing