Update git submodules

* Update docs/submodules/releng from branch 'master'
  - Merge "prototypes: xci: scripts: Add update-osa-version-files.sh script"
  - prototypes: xci: scripts: Add update-osa-version-files.sh script

    Add new prototypes/xci/scripts/update-osa-version-files.sh which can be
    used to update the XCI ansible-role-requirements.yml file as well as the
    OSA pinned SHA string. This file is using the upstream
    'sources-branch-updater-lib.sh' library from the openstack-ansible
    repository.

    Change-Id: I51b88c50cb2bffe0cf1b7aa054a5b237103fd92f
    Signed-off-by: Markos Chandras <mchandras@suse.de>

diff --git a/docs/submodules/releng b/docs/submodules/releng
index 0f10321..ef31c23 160000 (submodule)
--- a/docs/submodules/releng
+++ b/docs/submodules/releng
@@ -1 +1 @@
-Subproject commit 0f1032109fd2e6f576afb4696bfc5a069474c012
+Subproject commit ef31c232e9ec0d4bb8ec992a6541ba51a1eee2df