mfd: rt5033: Add Richtek RT5033 driver core.

This patch adds a new driver for Richtek RT5033 driver.
RT5033 is a Multifunction device which includes battery charger, fuel gauge,
flash LED current source, LDO and synchronous Buck converter. It is interfaced
to host controller using I2C interface.

Signed-off-by: Beomho Seo <beomho.seo@samsung.com>
Acked-by: Chanwoo Choi <cw00.choi@samsung.com>
Signed-off-by: Lee Jones <lee.jones@linaro.org>
diff --git a/drivers/mfd/Kconfig b/drivers/mfd/Kconfig
index 2e6b731..9cd2af6 100644
--- a/drivers/mfd/Kconfig
+++ b/drivers/mfd/Kconfig
@@ -623,6 +623,18 @@
 	  types of memory cards, such as Memory Stick, Memory Stick Pro,
 	  Secure Digital and MultiMediaCard.
 
+config MFD_RT5033
+	tristate "Richtek RT5033 Power Management IC"
+	depends on I2C=y
+	select MFD_CORE
+	select REGMAP_I2C
+	help
+	  This driver provides for the Richtek RT5033 Power Management IC,
+	  which includes the I2C driver and the Core APIs. This driver provides
+	  common support for accessing the device. The device supports multiple
+	  sub-devices like charger, fuel gauge, flash LED, current source,
+	  LDO and Buck.
+
 config MFD_RTSX_USB
 	tristate "Realtek USB card reader"
 	depends on USB