drm/vmwgfx: Update device headers

Historically our device headers have been forked versions of the
internal device headers, this has made maintaining them a bit
of a burden. To fix the situation, going forward, the device headers
will be verbatim copies of the internal headers.
To do that the driver code has to be adapted to use pristine
device headers. This will make future update to the device
headers trivial and automatic.

Signed-off-by: Zack Rusin <zackr@vmware.com>
Reviewed-by: Martin Krastev <krastevm@vmware.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20210615182336.995192-2-zackr@vmware.com