video: backlight: Drop default m for {LCD,BACKLIGHT_CLASS_DEVICE}

video: backlight: Drop default m for {LCD,BACKLIGHT_CLASS_DEVICE}

When running "make oldconfig" on a .config where
CONFIG_BACKLIGHT_LCD_SUPPORT is not set, two new config options
("Lowlevel LCD controls" and "Lowlevel Backlight controls") appear, both
defaulting to "m".

Drop the "default m", as options should default to disabled, and because
several driver config options already select LCD_CLASS_DEVICE or
BACKLIGHT_CLASS_DEVICE when needed.

Fixes: 8c5dc8d9f19c7992 ("video: backlight: Remove useless BACKLIGHT_LCD_SUPPORT kernel symbol")
Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
Reviewed-by: Daniel Thompson <daniel.thompson@linaro.org>
Signed-off-by: Lee Jones <lee.jones@linaro.org>