virtio-gpu: add VIRTIO_GPU_F_RESOURCE_UUID feature

virtio-gpu: add VIRTIO_GPU_F_RESOURCE_UUID feature

This feature allows the guest to request a UUID from the host for a
particular virtio_gpu resource. The UUID can then be shared with other
virtio devices, to allow the other host devices to access the
virtio_gpu's corresponding host resource.

Signed-off-by: David Stevens <stevensd@chromium.org>
Acked-by: Michael S. Tsirkin <mst@redhat.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20200818071343.3461203-3-stevensd@chromium.org
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>