The openmpi from SP2 requires libpsm2. libpsm2 build depends on git without
clear reason. To avoid inflating ring1 even more that dependency needs to be
removed so I can stage openmpi for 42.2

So please

- remove the build requirement to git, pass the version number to the Makefile
instead so the Makefile doesn't have to guess.
- generate the tarball of libpsm2 using a obs _service file, see aaa_base as
example
- refer to the proper upstream git in the spec file. Right now it's not
possible to see where the sources come from.
- submit libpsm2 to Factory!