Update git submodules

* Update docs/submodules/yardstick from branch 'master'
  - Merge "Remove redundancy file and do relative modification"
  - Remove redundancy file and do relative modification

    Change-Id: If6f672a2cbe218a20e3d8f3d093d31f6887d7ca3
    Signed-off-by: chenjiankun <chenjiankun1@huawei.com>

diff --git a/docs/submodules/yardstick b/docs/submodules/yardstick
index bf15098..4a5bc16 160000 (submodule)
--- a/docs/submodules/yardstick
+++ b/docs/submodules/yardstick
@@ -1 +1 @@
-Subproject commit bf15098782f77d750313a60cb2d4ae61529b369d
+Subproject commit 4a5bc16d841221e8ac7853b3044e50af0c8143d2