UPSTREAM: pwm: Move the enabled/disabled info into pwm_state

UPSTREAM: pwm: Move the enabled/disabled info into pwm_state

Prepare the transition to PWM atomic update by moving the enabled and
disabled state into the pwm_state struct. This way we can easily update
the whole PWM state by copying the new state in the ->state field.

Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
(cherry picked from commit 09a7e4a3d9fcb95ade2cb02167e85fbeb8315ce0)

Change-Id: I38808d868c7e73f0ffd49cfb6c0b4b45fa911613
Signed-off-by: David Wu <david.wu@rock-chips.com>