Switch packstack o-p-m branch to master-patches

The o-p-m master-patches branch contains rpm released master version of
o-p-m plus rpm patches applied to it ensuring that packstack will work
with it as in some cases master o-p-m is unusable for packstack.

Change-Id: Ib4e642bb96de1d87a5d36c20d5e2d4e2650353be