Fix missing openstack::corosync dependency for HA services

W/o this fix, pacemaker and corosync could be installed too
late causing pcs resource start operation timed out.
Also, ::corosync class could install pacemaker and corosync
packages out of openstack::corosync class evaluation, but we
want these packages installed while openstack::corosync is being
evaluated as well.

The solution is:
* ensure all pcs provided services will be
  evaluated after openstack::corosync class.
* add missing anchor dependency for ::corosync class call
  in openstack::corosync

Related-bug: #1390745

Change-Id: Icea3cdbb857a742cc35705f4de3b2cfba1847d1c
Signed-off-by: Bogdan Dobrelya <bdobrelia@mirantis.com>
Merge "Fix missing openstack::corosync dependency for HA services"