Update git submodules

* Update docs/submodules/functest from branch 'master'
  - Merge "Update graphs in userguide"
  - Update graphs in userguide

    1. Functest structural concept
    2. Clearwater architecture

    Change-Id: I88e39d6d08f1eb28a389d2b8a7a1669295f6aa49
    Signed-off-by: Linda Wang <wangwulin@huawei.com>

diff --git a/docs/submodules/functest b/docs/submodules/functest
index 1652a91..8813a7d 160000 (submodule)
--- a/docs/submodules/functest
+++ b/docs/submodules/functest
@@ -1 +1 @@
-Subproject commit 1652a913ee3085318a65711013975af4b5cbc341
+Subproject commit 8813a7d33fc632cdbeaa7cfd126976e6a57c68ea