Adds support for running burnin tests on GPUs using gpu-burn[1]. Also refactors stress-ng code to be a bit cleaner. Requires gpu-burn to be pre-installed within the IPA. * https://github.com/wilicc/gpu-burn Co-Authored-By: Scott Solkhon <scottsolkhon@gmail.com> Closes-Bug: #2069085 Change-Id: I8f8cace6ebc2b7f1c245c82a64609cdfc1c492f9