Update git submodules

* Update docs/submodules/releng from branch 'master'
  - Fix the output of repo list to be 'repo, tag, ref'

    This was changed in a previous commit and causes calls to 'git branch'
    during the verification job to fail.

    Change-Id: I71c248abecf030658371b810d403e1f460933946
    Signed-off-by: Trevor Bramwell <tbramwell@linuxfoundation.org>

diff --git a/docs/submodules/releng b/docs/submodules/releng
index 0f8bd83..1590a4f 160000 (submodule)
--- a/docs/submodules/releng
+++ b/docs/submodules/releng
@@ -1 +1 @@
-Subproject commit 0f8bd836b9b6d1017a5564cc0e9a3beae4736436
+Subproject commit 1590a4f64211574ad7a96bb81ad498e4a34fbbd0