`libvdrm` is unconditionally linked to `libvulkan_freedreno` which isn't available without the `virtio` subdirectory being included. It has been gated behind the `virtio` KMD to prevent linking errors in other cases as it's not necessary.
Signed-off-by: Mark Collins <mark@igalia.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/26100>