hwmon: lis3: regulator control

Based on pm_runtime control, turn lis3 regulators on and off.
Perform context save and restore on transitions.

Feature is optional and must be enabled in platform data.

Signed-off-by: Samu Onkalo <samu.p.onkalo@nokia.com>
Acked-by: Jonathan Cameron <jic23@cam.ac.uk>
Acked-by: Eric Piel <eric.piel@tremplin-utc.net>
Signed-off-by: Guenter Roeck <guenter.roeck@ericsson.com>
diff --git a/include/linux/lis3lv02d.h b/include/linux/lis3lv02d.h
index 0e8a346..c4a4a52 100644
--- a/include/linux/lis3lv02d.h
+++ b/include/linux/lis3lv02d.h
@@ -64,6 +64,8 @@
 	s8 axis_x;
 	s8 axis_y;
 	s8 axis_z;
+#define LIS3_USE_REGULATOR_CTRL 0x01
+	u16 driver_features;
 	int (*setup_resources)(void);
 	int (*release_resources)(void);
 	/* Limits for selftest are specified in chip data sheet */