Allow conditional pick of ppc64le runner
We have two runners - p8 and p9 - but they are not equally supported. Thus we need to correctly pick the one we need in the pipeline. We have a few scenarios:
- Any builder is ok to use - default tag, anything can be picked
- Require a p8 builder: the pipeline will specify the tag suffix of "-p8" to ensure the p8 will be picked. This would be the case for e.g. RHEL7 if we start doing native builds there.
- Require a p9 builder: the pipeline will specify the tag suffix of "-p9" to ensure p9 will be picked. This would be the case for e.g. c9s.
Signed-off-by: Veronika Kabatova vkabatov@redhat.com