Update git submodules

* Update docs/submodules/yardstick from branch 'master'
  - Add API to upload pod.yaml file

    JIRA: YARDSTICK-687

    We need a API to upload a pod.yaml file to /etc/yardstick/pod.yaml.

    API: /yardstick/env/action
    method: POST
    param:
    {
        'action': 'upload_pod_file',
        'file': file object
    }

    Change-Id: I3d25df364da10aaf34f995e948e1704235a40f6f
    Signed-off-by: chenjiankun <chenjiankun1@huawei.com>

diff --git a/docs/submodules/yardstick b/docs/submodules/yardstick
index cd5bb5f..c04372b 160000 (submodule)
--- a/docs/submodules/yardstick
+++ b/docs/submodules/yardstick
@@ -1 +1 @@
-Subproject commit cd5bb5f2dd2ec89e6c814c2771402aa8e39e10ef
+Subproject commit c04372b8630169a3fcc4b52e8d2b935f110519a6