Add stables to patchbot for *-powervm
Add stables to patchbot for *-powervm

Have patchbot report *-powervm patches to stable/ocata and stable/pike
in #openstack-powervm.

Change-Id: Ibd4a7a5273927462cf847d1af1cd26c3691fa9ef

openstack-infra/project-config,openstack-infra/project-config