regulator: add userspace-consumer driver

The userspace-consumer driver allows control of voltage and current
regulator state from userspace. This is required for fine-grained
power management of devices that are completely controller by userspace
applications, e.g. a GPS transciever connected to a serial port.

Signed-off-by: Mike Rapoport <mike@compulab.co.il>
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 707da4d2..5bec17c 100644
--- a/drivers/regulator/Kconfig
+++ b/drivers/regulator/Kconfig
@@ -47,6 +47,16 @@
 
           If unsure, say no.
 
+config REGULATOR_USERSPACE_CONSUMER
+	tristate "Userspace regulator consumer support"
+	default n
+	help
+	  There are some classes of devices that are controlled entirely
+	  from user space. Usersapce consumer driver provides ability to
+	  control power supplies for such devices.
+
+          If unsure, say no.
+
 config REGULATOR_BQ24022
 	tristate "TI bq24022 Dual Input 1-Cell Li-Ion Charger IC"
 	default n