Headers: Sync drm{,_mode}.h with the kernel

Generated using make headers_install, based on drm-misc-next commit
5db06a8a98f515f67446a69c57577c4c363ec65d.

This clarifies the comments around modifiers such that they are
per-framebuffer rather than per-plane, adds the beginnings of aspect
ratio mode flags, link status properties, and updates the 'reserved'
field from vblank events to include the CRTC ID.

v2: Split into separate patch, pull in full kernel changes.
v3: Undo revert of connector-type enums, since it is not actually
    harmful.

Signed-off-by: Daniel Stone <daniels@collabora.com>
Reviewed-by: Emil Velikov <emil.velikov@collabora.com>