leds: leds-mc13783: Use proper "max_brightness" value fo LEDs

Instead of using maximum value of 255 and shift it to appropriate
LED duty cycle, this patch introduce a helper to use proper maximum
value for each LED.

Signed-off-by: Alexander Shiyan <shc_work@mail.ru>
Signed-off-by: Bryan Wu <cooloney@gmail.com>
1 file changed