Only set the stonith property on the pacemaker_master node

Only set the stonith property on the pacemaker_master node

It makes little sense to enforce the stonith property on remote nodes and/or
all cluster nodes. We can just enforce it once on the pacemaker_master
node as it is a cluster-wide property anyway. We can also remove the
tripleo::fencing -> pacemaker::stonith constraint in the pacemaker
remote profile now as the fencing stuff happens on step 5 anyway and
the property is set at step 1.

While this works in general it creates extra CIB changes for nothing and
slows down the deployment.

Change-Id: Ifef08033043a4cc90a6261e962d2fdecdf275650
Closes-Bug: #1696336