virgl vendor id should probably be little more generic now.
I think I picked this becuase the virtio pci id space was under
RH's name and they did pay for it, but at this point I think it's
better to just use something generic.
Reviewed-by: Gert Wollny <gert.wollny@collabora.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/5483>