Update git submodules

* Update docs/submodules/releng from branch 'master'
  - Merge "Create Stable Branch Jobs for pharos"
  - Create Stable Branch Jobs for pharos

    Change-Id: I4d768151505cf5310564fb51c250b87abb2519c8
    Signed-off-by: jenkins-ci <jenkins-opnfv-ci@opnfv.org>
    Signed-off-by: Trevor Bramwell <tbramwell@linuxfoundation.org>

diff --git a/docs/submodules/releng b/docs/submodules/releng
index f1c7159..21225d8 160000 (submodule)
--- a/docs/submodules/releng
+++ b/docs/submodules/releng
@@ -1 +1 @@
-Subproject commit f1c7159f44e46a17bb8278be1831a2ab6206572f
+Subproject commit 21225d89c5463dc1e5b0a29bbc8f61dc651bb5f8