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: NSamu Onkalo <samu.p.onkalo@nokia.com>
Acked-by: NJonathan Cameron <jic23@cam.ac.uk>
Acked-by: NEric Piel <eric.piel@tremplin-utc.net>
Signed-off-by: NGuenter Roeck <guenter.roeck@ericsson.com>