Add DRM_DISPLAY_CONNECTOR. This got introduced with the bridge rework
Which renamed among others DRM_DUMB_VGA_DAC.

Link: https://lore.kernel.org/r/20200427134003.45188-3-max.krummenacher@toradex.comSigned-off-by: Max Krummenacher <max.krummenacher@toradex.com>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>