While libvirt is the only one that actually uses the compute host info
during this check, I think that it's an entirely reasonable thing to
pass to each hypervisor when doing the "can I migrate to this host"
check. Thus, I've added it excplicitly, without a gating check of
the capabilities.
Related to bp:no-db-compute
Change-Id: I7049879fcec3894165f1bece9beeb045ed78c94b