Update git submodules

* Update docs/submodules/yardstick from branch 'master'
  - Merge "NSB Prox minor refactor of BNG"
  - NSB Prox minor refactor of BNG

    JIRA: YARDSTICK-802

    - Updated the BNG code with minor refactor.
    - Corrected the CPE core name
    - Update binsearch traffic profile with 64B

    Change-Id: Iae0be766edb986520045655fa567651711813a8b
    Signed-off-by: Abhijit Sinha <abhijit.sinha@intel.com>

diff --git a/docs/submodules/yardstick b/docs/submodules/yardstick
index 89e17d5..6628dc3 160000 (submodule)
--- a/docs/submodules/yardstick
+++ b/docs/submodules/yardstick
@@ -1 +1 @@
-Subproject commit 89e17d5f72ba5cf9441d26f52d8cf8710946ed40
+Subproject commit 6628dc3d193a93f9af3295c3e02b0747d8cb73e0