pwm: imx27: Don't disable clocks at device remove time

The .remove() callback is not supposed to modify hardware state. This is
in the responsibility of the PWM consumer.

After the PWM was disabled the clocks are off (apart from a bug that is
fixed in the next patch), so unbinding the driver either stops the PWM
(which it should not) or disables already disabled clocks yielding
warnings from the clk core.

So just drop the call to disable the clocks. (Which BTW was also in the
wrong order because the call makes the PWM unfunctional and so should
have come only after pwmchip_remove()).

Fixes: 9f4c8f96 ("pwm: imx: Add ipg clock operation")
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>