Update git submodules

* Update docs/submodules/releng from branch 'master'
  to 8515c5dec75ed3186dfc4b321bc9f0d11561d414
  - Merge "Add all Functest gate views"
  - Add all Functest gate views

    Change-Id: I0463926ea1e3c1e93ac160ea3946f358cfc27585
    Signed-off-by: Cédric Ollivier <cedric.ollivier@orange.com>

diff --git a/docs/submodules/releng b/docs/submodules/releng
index 23b53a1..8515c5d 160000 (submodule)
--- a/docs/submodules/releng
+++ b/docs/submodules/releng
@@ -1 +1 @@
-Subproject commit 23b53a1fe78937d6391b89d1b11587419815b708
+Subproject commit 8515c5dec75ed3186dfc4b321bc9f0d11561d414