Update git submodules

* Update docs/submodules/yardstick from branch 'stable/fraser'
  - Add support for restarting a service

    JIRA: YARDSTICK-1138

    Change-Id: Id57defb574eb7e0f5be81b52803cdb05f46796ab
    Signed-off-by: Dimitrios Markou <mardim@intracom-telecom.com>
    (cherry picked from commit 131b9f04a360ccc894510a275bd33c57634608fc)

diff --git a/docs/submodules/yardstick b/docs/submodules/yardstick
index c778b24..57045b4 160000 (submodule)
--- a/docs/submodules/yardstick
+++ b/docs/submodules/yardstick
@@ -1 +1 @@
-Subproject commit c778b2494c4280035193a324a230b66ab9081300
+Subproject commit 57045b4e11ecffa256ec084919d6d34b9abaa109