Update git submodules

Update git submodules

* Update docs/submodules/releng from branch 'master'
  - Merge "jjb: xci: bifrost-verify-jobs: Disable OPNFV bifrost jobs"
  - jjb: xci: bifrost-verify-jobs: Disable OPNFV bifrost jobs

    The jobs are unmaintained and broken for months. Upstream already has
    jobs for all 3 distributions so there is little value to test a similar
    scenario on the OPNFV side. As such, lets disable them and save some
    hardware resources for XCI.

    Change-Id: I0ab7d51f44bdeb6f630671e8d05dd2baf67d756c
    Signed-off-by: Markos Chandras <mchandras@suse.de>