vfio/hisi_acc: Use the new device life cycle helpers

Tidy up @probe so all migration specific initialization logic is moved
to migration specific @init callback.

Remove vfio_pci_core_{un}init_device() given no user now.

Signed-off-by: Yi Liu <yi.l.liu@intel.com>
Signed-off-by: Kevin Tian <kevin.tian@intel.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Reviewed-by: Shameer Kolothum <shameerali.kolothum.thodi@huawei.com>
Link: https://lore.kernel.org/r/20220921104401.38898-5-kevin.tian@intel.com


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