Four of the LCD panel drivers depend on the backlight class,
so add the dependency in Kconfig.
Selecting the BACKLIGHT_CLASS_DEVICE symbol does not generally
work since it has other dependencies.
Signed-off-by: NArnd Bergmann <arnd@arndb.de>
[tomi.valkeinen@ti.com: changed also N8x0 panel]
Signed-off-by: NTomi Valkeinen <tomi.valkeinen@ti.com>