migration: privatize colo interfaces

Remove private migration interfaces from net/colo-compare.c and push them
to migration/colo.c.

Signed-off-by: Steve Sistare <steven.sistare@oracle.com>
Link: https://lore.kernel.org/r/1710179338-294359-10-git-send-email-steven.sistare@oracle.com
Signed-off-by: Peter Xu <peterx@redhat.com>
3 files changed