The ICS object uses a post_load() handler which is implicitly relying
on the fact that the internal state of the ICS and ICP objects has
been restored but this is not guaranteed. So, let's move the code
under the post_load() handler of the machine where we know the objects
have been fully restored.

The icp_resend() handler of the XICSFabric QOM interface is also
removed as it is now obsolete.
Signed-off-by: NCédric Le Goater <clg@kaod.org>
Signed-off-by: NDavid Gibson <david@gibson.dropbear.id.au>