Update git submodules

* Update docs/submodules/samplevnf from branch 'stable/euphrates'
  - update rest api table

    Change-Id: I71f8b419a8b28bc3c9208c8902b91d06bc4653de
    Signed-off-by: Deepak S <deepak.s@linux.intel.com>

diff --git a/docs/submodules/samplevnf b/docs/submodules/samplevnf
index e44592e..6aab5b8 160000 (submodule)
--- a/docs/submodules/samplevnf
+++ b/docs/submodules/samplevnf
@@ -1 +1 @@
-Subproject commit e44592e08dd0a9f6a64586e11374f8e9e6285fa0
+Subproject commit 6aab5b8051cbc73962598ebd54c550f9bc3bd916