Update git submodules

Update git submodules

* Update docs/submodules/releng from branch 'master'
  - Merge "Update the repo script to only list repos once"
  - Update the repo script to only list repos once

    When projects have multiple releases (ex 6.0, 6.1) the repos would be
    listed multiple times when only wanting repo names. This change still
    supports listing the repos when they have multiple versions.

    Change-Id: I7b0c96649b5486d91b177f95cf175bebcb53815b
    Signed-off-by: Trevor Bramwell <tbramwell@linuxfoundation.org>