CI: Add automatic retry for test.py jobs

It is not uncommon for some of the QEMU-based jobs to fail not because
of a code issue but rather because of a timing issue or similar problem
that is out of our control. Make use of the keywords that Azure and
GitLab provide so that we will automatically re-run these when they fail
2 times. If they fail that often it is likely we have found a real issue
to investigate.

Signed-off-by: Tom Rini <trini@konsulko.com>
Reviewed-by: Simon Glass <sjg@chromium.org>