Update git submodules

* Update docs/submodules/releng from branch 'master'
  - Merge "Add Samplevnf project release tag and notes"
  - Add Samplevnf project release tag and notes

    Change-Id: I83347286490344912593a122fc47013d5fcf7225
    Signed-off-by: Deepak S <deepak.s@linux.intel.com>
    Signed-off-by: Trevor Bramwell <tbramwell@linuxfoundation.org>

diff --git a/docs/submodules/releng b/docs/submodules/releng
index aa3ba85..9fab1b5 160000 (submodule)
--- a/docs/submodules/releng
+++ b/docs/submodules/releng
@@ -1 +1 @@
-Subproject commit aa3ba85c8f09c907f094d184232386b63616cfa5
+Subproject commit 9fab1b51ab2e1ead7df8d51aaa28c2b6cc28e704