This fixes a FreeBSD build error from
commit a11a0e6e8473fec6127b263a33f892135097648f
Author: Rafael Fonseca <r4f4rfs@gmail.com>
Date: Tue Mar 24 17:14:30 2020 +0100
bhyve: move video default logic to driver
Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>