We're going to be calling some methods from AllocImpl directly in
Registration::new() - which means that the rust compiler needs to know that
our associated AllocImpl trait uses us as a Driver trait. Otherwise, it'll
complain about a missing trait bound.

The simplest way to do this is to just add this as a trait bound for the
associated Driver::Object trait.

Signed-off-by: Lyude Paul <lyude@redhat.com>

* Drop fbdev module entirely and move setup_fbdev() into AllocImpl (Daniel)

You gotta squash this, shmem is going to get aded with the introduction of
the fbdev types since we specify it on the AllocImpl trait now

This reverts commit 74b50c63.

V3:
* Get rid of Kms, long live KmsDriver
  After Daniel pointed out that we should just make KmsDriver a supertrait
  of Driver, it immediately occurred to me that there's no actual need for
  Kms to be a separate trait at all. So, drop Kms entirely and move its
  requirements over to KmsDriver.

* Add safety comments for ModeObject implementation

* Fix typo on KmsImpl documentation

* Add safety comments to implementation of AsRawPlane

* Make AsRawPlane unsafe, since we need a guarantee that `as_raw()` always
  returns a valid pointer to an initialized drm_plane.

* Add safety comments to AsRawCrtc implementation

* Make AsRawCrtc unsafe, as we need a guarantee that `as_raw()` will always
  return a pointer to a valid `drm_crtc`.

* Add safety comments for AsRawEncoder

* Make AsRawEncoder unsafe so that we have a guarantee that `as_raw()`
  always returns a valid pointer.

* Add safety comments to AsRawConnector implementation

* Make AsRawConnector an unsafe trait, we need a guarantee that as_raw()
  always returns a valid pointer.

V3:
* Add safety comment to ModeObject implementation

V3:
* Add safety comments for ModeObject implementation

V3:
* Add safety comment to implementation of ModeObject

V3:
* Add safety comment to implementation of ModeObject

V3:
* Add safety comment to implementation of ModeObject

V3:
* Add safety comment for implementation of ModeObject

V3:
* Add safety comment for implementation of ModeObject

V3:
* Add safety comments for ModeObject implementation