video: Add auxiliary display drivers to Graphics support menu

The drivers in this subsystem are for either character-based or monochrome
LCD controllers. Which can fall into the same category of the DRM/KMS and
fbdev drivers, that are located under the "Graphics support" menu.

Add the auxdisplay drivers there as well to have all display drivers under
the same menu.

Suggested-by: Thomas Zimmermann <tzimmermann@suse.de>
Signed-off-by: Javier Martinez Canillas <javierm@redhat.com>
Reviewed-by: Arnd Bergmann <arnd@arndb.de>
Tested-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Helge Deller <deller@gmx.de>
Acked-by: Miguel Ojeda <ojeda@kernel.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20230719081544.741051-2-javierm@redhat.com