CONFIG_VFIO_PCI was not "default y" - and once you do that, it is also
important to disable it if PCI is not there.
Reported-by: Alex Williamson <alex.williamson@redhat.com>
Tested-by: Alex Williamson <alex.williamson@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>