Update git submodules

* Update docs/submodules/releng from branch 'master'
  - Merge "Build arm images and publish manifests"
  - Build arm images and publish manifests

    It mainly follows the Functest docker jjb.

    Change-Id: Ia86082cfd5d2f19496e7801441e005ffc88595a3
    Signed-off-by: Cédric Ollivier <cedric.ollivier@orange.com>

diff --git a/docs/submodules/releng b/docs/submodules/releng
index cc3a970..e5550dd 160000 (submodule)
--- a/docs/submodules/releng
+++ b/docs/submodules/releng
@@ -1 +1 @@
-Subproject commit cc3a9709bc7ae4c3a5688d30d6f87bda6f12f513
+Subproject commit e5550dd9216ca961f26662de0d379f116d74e89f