Update git submodules

* Update docs/submodules/clover from branch 'master'
  - Merge "Create document structure"
  - Create document structure

    See http://docs.opnfv.org/en/latest/how-to-use-docs/documentation-guide.html

    Note the structure stands on the view of whole OPNFV platform.

    Change-Id: Id2ac36cb6f30d6d2d54dbda9f6a77b76648aa4b0
    Signed-off-by: Yujun Zhang <zhang.yujunz@zte.com.cn>

diff --git a/docs/submodules/clover b/docs/submodules/clover
index 3767322..61c6ac4 160000 (submodule)
--- a/docs/submodules/clover
+++ b/docs/submodules/clover
@@ -1 +1 @@
-Subproject commit 3767322931b6be4bf5e229352013eaba559d7fba
+Subproject commit 61c6ac4fe000f96826bc5ce6755cf6bc360e3aef