drivers: regulators: depend on MFD_MAX8998

The MAX8998-pmic driver requires a core driver for all io operations. Like
other regulator driver make it depend of the required MFD io driver.
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>

drivers/regulator/Kconfig

@@ -102,8 +102,7 @@ config REGULATOR_MAX8925
 
 config REGULATOR_MAX8998
 	tristate "Maxim 8998 voltage regulator"
-	depends on I2C
-	default n
+	depends on MFD_MAX8998
 	help
 	  This driver controls a Maxim 8998 voltage output regulator
 	  via I2C bus. The provided regulator is suitable for S3C6410