conf: allow display and ramfb for vfio pci hostdevs

conf: allow display and ramfb for vfio pci hostdevs

We already allow the user to specify display="on" and ramfb="on" for
mdev host devices. But newer GPU models will no longer use the mdev
framework, so we should enable this same functionality for other
non-mdev passthrough PCI devices.

Resolves: https://issues.redhat.com/browse/RHEL-28808

Signed-off-by: Jonathon Jongsma <jjongsma@redhat.com>
Reviewed-by: Michal Privoznik <mprivozn@redhat.com>