[rdo-dev] [ppc64le] test-day-tools job for ppc64le

Hello RDOers, I've had https://review.rdoproject.org/r/#/c/14739/ up for a little bit now and was hoping to get some more eyes on it. It enables a test-day-tools job that grabs a ppc64le node instead of an x86_64 one. This allows us to iterate on a job to build ppc64le containers. If you could give it a look it would be much appreciated. Thanks! Mike Turek <mjturek on freenode>