Update git submodules

* Update docs/submodules/releng from branch 'master'
  to 3bcf89732bd9ffba1f809566c1d81d62286bc5da
  - Create Xena branches

    Change-Id: I61e6bf9a4564e4d6faaea0042881c8da32a1a089
    Signed-off-by: Cédric Ollivier <cedric.ollivier@orange.com>

diff --git a/docs/submodules/releng b/docs/submodules/releng
index bff2878..3bcf897 160000 (submodule)
--- a/docs/submodules/releng
+++ b/docs/submodules/releng
@@ -1 +1 @@
-Subproject commit bff28787740d77257ae44cc7f208b29297a69d8e
+Subproject commit 3bcf89732bd9ffba1f809566c1d81d62286bc5da