Update git submodules

* Update docs/submodules/releng from branch 'master'
  - Merge "add release notes for container4nfv"
  - add release notes for container4nfv

    Change-Id: Ided8302e6d80e330bb3b469b2fead23be876c5bc
    Signed-off-by: Guo Ruijing <ruijing.guo@intel.com>

diff --git a/docs/submodules/releng b/docs/submodules/releng
index ea195b2..d207c2c 160000 (submodule)
--- a/docs/submodules/releng
+++ b/docs/submodules/releng
@@ -1 +1 @@
-Subproject commit ea195b23cebbe9a646db0fe293c1dbd5e4a8a3ae
+Subproject commit d207c2c24426cb4536f49aa035a697213463e83d