Configure NTP on HA Controller

I was unsure whether to put the $ntp_servers into pacemaker::params but it seemed to me we shouldn't call map_params from classes outside quickstack::pacemaker:: namespace (because map_params looks into pacemaker::params). So i put it directly into the quickstack::openstack_common class, it is still overridable on the HA Controller host group and we might reuse it from the non-HA hostgroups in the future.