Merge remote-tracking branch 'remotes/stsquad/tags/pull-testing-and-misc-271020-1...

Merge remote-tracking branch 'remotes/stsquad/tags/pull-testing-and-misc-271020-1' into staging

Testing and gitdm updates

  - add some more individual contributors
  - include SDL2 in centos images
  - skip checkpatch check when no commits found
  - use random port for gdb reverse debugging
  - make gitlab use it's own mirrors to clone
  - fix detection of make -nqp

# gpg: Signature made Tue 27 Oct 2020 09:55:55 GMT
# gpg:                using RSA key 6685AE99E75167BCAFC8DF35FBD0DB095A9E2A44
# gpg: Good signature from "Alex Bennée (Master Work Key) <alex.bennee@linaro.org>" [full]
# Primary key fingerprint: 6685 AE99 E751 67BC AFC8  DF35 FBD0 DB09 5A9E 2A44

* remotes/stsquad/tags/pull-testing-and-misc-271020-1:
  makefile: handle -n / -k / -q correctly
  gitlab-ci: Clone from GitLab itself
  tests/acceptance: pick a random gdb port for reverse debugging
  scripts: fix error from checkpatch.pl when no commits are found
  gitlab: skip checkpatch.pl checks if no commit delta on branch
  tests/docker/dockerfiles/centos: Use SDL2 instead of SDL1
  contrib/gitdm: Add more individual contributors
  Adding ani's email as an individual contributor

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>