LP3971 PMIC regulator driver (updated and combined version)

This patch adds regulator drivers for National Semiconductors LP3971 PMIC.
This LP3971 PMIC controller has 3 DC/DC voltage converters and 5 low
drop-out (LDO) regulators. LP3971 PMIC controller uses I2C interface.

Reviewed-by: Kyungmin Park <kyungmin.park@samsung.com>
Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
Acked-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Signed-off-by: Liam Girdwood <lrg@slimlogic.co.uk>
diff --git a/drivers/regulator/Kconfig b/drivers/regulator/Kconfig
index 5bec17c..f431779 100644
--- a/drivers/regulator/Kconfig
+++ b/drivers/regulator/Kconfig
@@ -110,4 +110,11 @@
 	 Say Y here to support the voltage regulators and convertors
 	 on PCF50633
 
+config REGULATOR_LP3971
+	tristate "National Semiconductors LP3971 PMIC regulator driver"
+	depends on I2C
+	help
+	 Say Y here to support the voltage regulators and convertors
+	 on National Semiconductors LP3971 PMIC
+
 endif