Update git submodules

* Update docs/submodules/yardstick from branch 'master'
  - Merge "Add API(v2) to delete openrc"
  - Add API(v2) to delete openrc

    JIRA: YARDSTICK-722

    API: /api/v2/yardstick/environments/openrcs/<openrc_id>
    METHOD: DELETE

    Change-Id: Ia0989fe74681654750af80ddb935bb3e63485f43
    Signed-off-by: chenjiankun <chenjiankun1@huawei.com>

diff --git a/docs/submodules/yardstick b/docs/submodules/yardstick
index 74c3ca1..3f1a658 160000 (submodule)
--- a/docs/submodules/yardstick
+++ b/docs/submodules/yardstick
@@ -1 +1 @@
-Subproject commit 74c3ca16d897abc6705eceefb0a737212dbe7f08
+Subproject commit 3f1a658fce4b3d81fa2b15ab1879fd37aad80760