Update git submodules

* Update docs/submodules/dovetail from branch 'master'
  - Remove the yardstick_tag and functest_tag

    These 2 commands can't work now.
    Also there is no need to support them, so remove them.

    JIRA: DOVETAIL-695

    Change-Id: I6707c7fc1d19fe06690cd14ef39f9d421d00a2bc
    Signed-off-by: xudan <xudan16@huawei.com>

diff --git a/docs/submodules/dovetail b/docs/submodules/dovetail
index 6dbc1a9..edf504a 160000 (submodule)
--- a/docs/submodules/dovetail
+++ b/docs/submodules/dovetail
@@ -1 +1 @@
-Subproject commit 6dbc1a9452d6c8451f759b7be73ac3986f6f4fd4
+Subproject commit edf504a4071b1d9300f72c5d83a22cda3bf2dc67