leds: make brightness type consistent across whole subsystem

Documentations states that brightness units type is enum led_brightness
and this is the type used by the led API functions. Adjust the type
of brightness variables in the struct led_classdev accordingly.
Signed-off-by: NJacek Anaszewski <j.anaszewski@samsung.com>
Acked-by: NKyungmin Park <kyungmin.park@samsung.com>
Cc: Richard Purdie <rpurdie@rpsys.net>
Signed-off-by: NBryan Wu <cooloney@gmail.com>

include/linux/leds.h

@@ -31,8 +31,8 @@ enum led_brightness {
 
 struct led_classdev {
 	const char		*name;
-	int			 brightness;
-	int			 max_brightness;
+	enum led_brightness	 brightness;
+	enum led_brightness	 max_brightness;
 	int			 flags;
 
 	/* Lower 16 bits reflect status */