virtio-gpu cross-domain context supersedes the downstream virtio-wl.
However, there's no compositor working well with cross-domain context
yet (sommelier from ChromeOS only works robustly with virtio-wl while
being pretty broken with cross-domain). So let's just drop the legacy
piece to avoid confusions.
Reviewed-by: Corentin Noël <corentin.noel@collabora.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/35680>