mfd: PCF50633 adc driver

This patch adds basic support for the PCF50633 ADC. The subtractive mode
is not supported yet.

Since we don't have adc subsystem, it currently lives in drivers/mfd.

Signed-off-by: Balaji Rao <balajirrao@openmoko.org>
Cc: Andy Green <andy@openmoko.com>
Acked-by: Jonathan Cameron <jonathan.cameron@gmail.com>
Signed-off-by: Samuel Ortiz <sameo@openedhand.com>
diff --git a/drivers/mfd/Makefile b/drivers/mfd/Makefile
index 23d4d10..138f9c4 100644
--- a/drivers/mfd/Makefile
+++ b/drivers/mfd/Makefile
@@ -38,4 +38,5 @@
 
 obj-$(CONFIG_PMIC_DA903X)	+= da903x.o
 
-obj-$(CONFIG_MFD_PCF50633)	+= pcf50633-core.o
\ No newline at end of file
+obj-$(CONFIG_MFD_PCF50633)	+= pcf50633-core.o
+obj-$(CONFIG_PCF50633_ADC)	+= pcf50633-adc.o
\ No newline at end of file