regulator: Make fixed voltage regulators visible in Kconfig

This allows users to enable or disable support for these regulators at
build time as they can for other regulators rather than having platforms
force the regulators to be built in.
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Signed-off-by: Liam Girdwood <lrg@slimlogic.co.uk>

drivers/regulator/Kconfig

@@ -29,8 +29,12 @@ config REGULATOR_DEBUG
 	  Say yes here to enable debugging support.
 
 config REGULATOR_FIXED_VOLTAGE
-	tristate
+	tristate "Fixed voltage regulator support"
 	default n
+	help
+	  This driver provides support for fixed voltage regulators,
+	  useful for systems which use a combination of software
+	  managed regulators and simple non-configurable regulators.
 
 config REGULATOR_VIRTUAL_CONSUMER
 	tristate "Virtual regulator consumer support"