Update git submodules

* Update docs/submodules/yardstick from branch 'stable/euphrates'
  - Merge "NSB "Prox" : Cleanup duplicated traffic profile" into stable/euphrates
  - NSB "Prox" : Cleanup duplicated traffic profile

    JIRA: YARDSTICK-848

    The NSB PROX MPLS test uses Binsearch traffic
    profile and the mpls traffic profile is a duplicate.

    Change-Id: Ie2124cebf306fd6917b70ecd7c23ae12ef4850dc
    Signed-off-by: Abhijit Sinha <abhijit.sinha@intel.com>
    (cherry picked from commit 1b9cc8a38a4866797bd49d006e22607b348f42ac)

diff --git a/docs/submodules/yardstick b/docs/submodules/yardstick
index 0de44ee..2160087 160000 (submodule)
--- a/docs/submodules/yardstick
+++ b/docs/submodules/yardstick
@@ -1 +1 @@
-Subproject commit 0de44ee068f246af766b7399574d1abfe95e1fd3
+Subproject commit 2160087b809fb5d52c51bd4abd6c0635f9917ca8