ide: move restart callback to common code

ide: move restart callback to common code

With BMDMA specific excised from the restart functions,
create a HBA-agnostic restart callback to be shared
between the different HBAs.

Change the callback registered with the vmstate_change
handler to always point to ide_restart_cb instead of
relying on the IDEDMAOps.restart_cb() member.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: John Snow <jsnow@redhat.com>
Message-id: 1424708286-16483-7-git-send-email-jsnow@redhat.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>