backlight: lp8788: Explicitly apply PWM config extracted from pwm_args

Call pwm_apply_args() just after requesting the PWM device so that the
polarity and period are initialized according to the information
provided in pwm_args.

This is an intermediate state, and pwm_apply_args() should be dropped as
soon as the atomic PWM infrastructure is in place and the driver makes
use of it.
Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>

drivers/video/backlight/lp8788_bl.c

@@ -145,6 +145,12 @@ static void lp8788_pwm_ctrl(struct lp8788_bl *bl, int br, int max_br)
 		}
 
 		bl->pwm = pwm;
+
+		/*
+		 * FIXME: pwm_apply_args() should be removed when switching to
+		 * the atomic PWM API.
+		 */
+		pwm_apply_args(pwm);
 	}
 
 	pwm_config(bl->pwm, duty, period);