pwm: fsl-ftm: set pwm_chip can_sleep flag

The implementation of .config(), .enable() and .disable() operations in this
driver may sleep, thus set pwm_chip can_sleep flag.
Signed-off-by: Axel Lin <axel.lin@ingics.com>
Acked-by: Xiubo Li <Li.Xiubo@freescale.com>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>

drivers/pwm/pwm-fsl-ftm.c

@@ -454,6 +454,7 @@ static int fsl_pwm_probe(struct platform_device *pdev)
 	fpc->chip.of_pwm_n_cells = 3;
 	fpc->chip.base = -1;
 	fpc->chip.npwm = 8;
+	fpc->chip.can_sleep = true;
 
 	ret = pwmchip_add(&fpc->chip);
 	if (ret < 0) {