Update git submodules

* Update docs/submodules/releng from branch 'master'
  - Merge "[Functest] Add DOCKER_TAG in Alpine images"
  - [Functest] Add DOCKER_TAG in Alpine images

    Change-Id: I8a8d46798ea73364cf0f2b66464d3628d6d572d3
    Signed-off-by: Jose Lausuch <jalausuch@suse.com>

diff --git a/docs/submodules/releng b/docs/submodules/releng
index fb88e7f..fb23c3c 160000 (submodule)
--- a/docs/submodules/releng
+++ b/docs/submodules/releng
@@ -1 +1 @@
-Subproject commit fb88e7f0213e138b9214a3e24dbecec73057acef
+Subproject commit fb23c3ca2ed8f6fd1f3e7f9f5c35a8a9cb81852f