Update git submodules

* Update docs/submodules/releng from branch 'master'
  to 6cf5d8c90fad9135a5087a4134429006f173e532
  - Defining stable/orinoco branch for Barometer, Kuberef and Thoth

    Change-Id: I9ddc9455c213989a59211fb4a163d6c1e7d41392
    Signed-off-by: Gergely Csatari <gergely.csatari@nokia.com>

diff --git a/docs/submodules/releng b/docs/submodules/releng
index a21cb3d..6cf5d8c 160000 (submodule)
--- a/docs/submodules/releng
+++ b/docs/submodules/releng
@@ -1 +1 @@
-Subproject commit a21cb3db6aeb8a34d83bfe3ceaa71f8ff84f15db
+Subproject commit 6cf5d8c90fad9135a5087a4134429006f173e532