Update git submodules

* Update docs/submodules/samplevnf from branch 'stable/euphrates'
  - Updating release notes of samplevnf

    Change-Id: I5c6854467bca41ab0ca5894e1a706a65eb68ef32
    Signed-off-by: Deepak S <deepak.s@linux.intel.com>

diff --git a/docs/submodules/samplevnf b/docs/submodules/samplevnf
index 1e0a40a..9258261 160000 (submodule)
--- a/docs/submodules/samplevnf
+++ b/docs/submodules/samplevnf
@@ -1 +1 @@
-Subproject commit 1e0a40a854ca2312aedad6f2c4eb55623cb2ed15
+Subproject commit 92582616007fdd250e121709bdf0ccef789cacdb