hwmon: (ltc2978) Add regulator support

Add simple on/off regulator support for ltc2978 and
other pmbus parts supported by the ltc2978 driver.

Signed-off-by: Alan Tull <atull@opensource.altera.com>
Cc: Guenter Roeck <linux@roeck-us.net>
Cc: Mark Brown <broonie@kernel.org>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
diff --git a/drivers/hwmon/pmbus/Kconfig b/drivers/hwmon/pmbus/Kconfig
index 6e1e493..a674cd8 100644
--- a/drivers/hwmon/pmbus/Kconfig
+++ b/drivers/hwmon/pmbus/Kconfig
@@ -47,15 +47,22 @@
 	  be called lm25066.
 
 config SENSORS_LTC2978
-	tristate "Linear Technologies LTC2974, LTC2978, LTC3880, and LTC3883"
+	tristate "Linear Technologies LTC2978 and compatibles"
 	default n
 	help
 	  If you say yes here you get hardware monitoring support for Linear
-	  Technology LTC2974, LTC2978, LTC3880, and LTC3883.
+	  Technology LTC2974, LTC2977, LTC2978, LTC3880, LTC3883, and LTM4676.
 
 	  This driver can also be built as a module. If so, the module will
 	  be called ltc2978.
 
+config SENSORS_LTC2978_REGULATOR
+	boolean "Regulator support for LTC2978 and compatibles"
+	depends on SENSORS_LTC2978 && REGULATOR
+	help
+	  If you say yes here you get regulator support for Linear
+	  Technology LTC2974, LTC2977, LTC2978, LTC3880, LTC3883, and LTM4676.
+
 config SENSORS_MAX16064
 	tristate "Maxim MAX16064"
 	default n