The backlight class is used to create userspace handles for
setting the OLED contrast.
Signed-off-by: NThomas Niederprüm <niederp@physik.uni-kl.de>
Acked-by: NMaxime Ripard <maxime.ripard@free-electrons.com>
Signed-off-by: NTomi Valkeinen <tomi.valkeinen@ti.com>