UPSTREAM: regulator: pwm: Adjust PWM config at probe time

UPSTREAM: regulator: pwm: Adjust PWM config at probe time

The PWM attached to a PWM regulator device might have been previously
configured by the bootloader.
Make sure the bootloader and linux config are in sync, and adjust the PWM
config if that's not the case.

Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com>
Acked-by: Mark Brown <broonie@kernel.org>
Acked-by: Brian Norris <briannorris@chromium.org>
Tested-by: Brian Norris <briannorris@chromium.org>
Tested-by: Heiko Stuebner <heiko@sntech.de>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
(cherry picked from commit fd4f99c4c3ce8ccd9b8ea751afc614a7624ecef2)

Change-Id: I06abddddc4666cd6510b6317795931f282e44eb0
Signed-off-by: David Wu <david.wu@rock-chips.com>