Update git submodules

* Update docs/submodules/samplevnf from branch 'stable/gambia'
  - Updating release notes for Gambia...

    Change-Id: Ide712ee94254b506a0ad88c95a7e01b789f00e48
    Signed-off-by: Deepak S <deepak.s@linux.intel.com>

diff --git a/docs/submodules/samplevnf b/docs/submodules/samplevnf
index bffb52a..66ee98f 160000 (submodule)
--- a/docs/submodules/samplevnf
+++ b/docs/submodules/samplevnf
@@ -1 +1 @@
-Subproject commit bffb52abba29f2b9c9e1288cfbfbace54d62eb9e
+Subproject commit 66ee98f3427439a4cdd56c9f67a25aec140a5c9c