regulator: MAX77686: Add Maxim 77686 regulator driver

Add driver for support max77686 regulator.
MAX77686 provides LDOs[1~26] and BUCKs[1~9]. It support to set or get the
volatege of regulator on max77686 chip with using regmap.

Signed-off-by: Chiwoong Byun <woong.byun@samsung.com>
Signed-off-by: Jonghwa Lee <jonghwa3.lee@samsung.com>
Signed-off-by: Myungjoo Ham <myungjoo.ham@samsung.com>
Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
Reviewed-by: Yadwinder Singh Brar <yadi.brar@samsung.com>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
diff --git a/drivers/regulator/Kconfig b/drivers/regulator/Kconfig
index c86b886..00ffe05 100644
--- a/drivers/regulator/Kconfig
+++ b/drivers/regulator/Kconfig
@@ -195,6 +195,14 @@
 	  via I2C bus. The provided regulator is suitable for S3C6410
 	  and S5PC1XX chips to control VCC_CORE and VCC_USIM voltages.
 
+config REGULATOR_MAX77686
+	tristate "Maxim 77686 regulator"
+	depends on MFD_MAX77686
+	help
+	  This driver controls a Maxim 77686 regulator
+	  via I2C bus. The provided regulator is suitable for
+	  Exynos-4 chips to control VARM and VINT voltages.
+
 config REGULATOR_PCAP
 	tristate "Motorola PCAP2 regulator driver"
 	depends on EZX_PCAP