mfd: Add mc13xxx i2c driver

Adds support for mc13xxx family ICs connected via i2c.

Signed-off-by: Marc Reilly <marc@cpdesign.com.au>
Acked-by: Oskar Schirmer <oskar@scara.com>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
diff --git a/drivers/mfd/Makefile b/drivers/mfd/Makefile
index 7ce5b5c..5dd6be7 100644
--- a/drivers/mfd/Makefile
+++ b/drivers/mfd/Makefile
@@ -55,6 +55,7 @@
 
 obj-$(CONFIG_MFD_MC13XXX)	+= mc13xxx-core.o
 obj-$(CONFIG_MFD_MC13XXX_SPI)	+= mc13xxx-spi.o
+obj-$(CONFIG_MFD_MC13XXX_I2C)	+= mc13xxx-i2c.o
 
 obj-$(CONFIG_MFD_CORE)		+= mfd-core.o