drivers: pwm: pwm_mcux_sctimer: Fix stopping PWM

By Starting the timer when period was set to 0, the SCTimer was giving
control of the pin back to the timer and over-riding the value written
to base->OUTPUT register. Consequently, the PWM timer was never
stopped and still using the previously configured period.

The PWM now correctly stops when setting the period to 0.

Signed-off-by: Guy Morand <guy.morand@bytesatwork.ch>

drivers/pwm/pwm_mcux_sctimer.c

@@ -73,11 +73,6 @@ static int mcux_sctimer_pwm_set_cycles(const struct device *dev,
 			base->OUTPUT |= (1UL << channel);
 		}
 
-		/* Make sure the PWM is setup */
-		if (data->period_cycles[channel] != 0) {
-			SCTIMER_StartTimer(config->base, kSCTIMER_Counter_U);
-		}
-
 		return 0;
 	}