Update git submodules

* Update docs/submodules/yardstick from branch 'master'
  - Merge "Add test case file and document of Tardstick TC056(HA_TC013)"
  - Add test case file and document of Tardstick TC056(HA_TC013)

    JIRA: YARDSTICK-778

    Change-Id: I271b42a24e9d1ee48e54bceb4517252d1f664d51
    Signed-off-by: tjuyinkanglin <14_ykl@tongji.edu.cn>

diff --git a/docs/submodules/yardstick b/docs/submodules/yardstick
index 4303528..b39fe54 160000 (submodule)
--- a/docs/submodules/yardstick
+++ b/docs/submodules/yardstick
@@ -1 +1 @@
-Subproject commit 4303528272c8a2ea2787868b0394722d8d07e7bb
+Subproject commit b39fe5457e846e734e980666bc209fb7c07a6bdc