pwm: imx27: Don't use pwm consumer API

Lowlevel driver callbacks are not supposed to use the consumer API
functions. Currently this works, but with the upcoming locking changes
this maybe results in dead locks. So directly access pwm->state.

Link: https://lore.kernel.org/r/20240126101624.2056801-2-u.kleine-koenig@pengutronix.de


Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>