Update git submodules

Update git submodules

* Update docs/submodules/releng from branch 'master'
  - [fuel, armband] Switch CI jobs to gambia

    - keep fraser jobs for Dovetail, schedule 4 CI runs / week / arch;
    - stop running Functest/Yardstick for fraser to cut down CI time;
    - reschedule master/gambia triggers to ensure an uniform CI POD
      allocation across the week;
    - enable gambia triggers;

    Change-Id: I2a66628ff3525cc9cbd4ffbb4b790633257b6cba
    Signed-off-by: Alexandru Avadanii <Alexandru.Avadanii@enea.com>