vfio/type1: revert "implement notify callback"

This is dead code.  Revert it.
  commit 487ace13 ("vfio/type1: implement notify callback")

Signed-off-by: Steve Sistare <steven.sistare@oracle.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Link: https://lore.kernel.org/r/1675184289-267876-7-git-send-email-steven.sistare@oracle.com


Signed-off-by: Alex Williamson <alex.williamson@redhat.com>