Update git submodules

* Update docs/submodules/dovetail from branch 'master'
  - Add License for the python scripts in folder offline

    Change-Id: I9c585f132c10ef726cd859e4abe3c9a874cbe0bc
    Signed-off-by: xudan <xudan16@huawei.com>

diff --git a/docs/submodules/dovetail b/docs/submodules/dovetail
index 1bbda3c..df237a6 160000 (submodule)
--- a/docs/submodules/dovetail
+++ b/docs/submodules/dovetail
@@ -1 +1 @@
-Subproject commit 1bbda3ceda250a3d28ee70e5d9f0ea09cc91e261
+Subproject commit df237a6439f6e335c01112ead5f6c72174a79efc