Update git submodules

* Update docs/submodules/dovetail from branch 'master'
  - simplify file existence check with os.path.isfile()

    Change-Id: I89d15e18c588c27ab41596119d5288cba6e4e02d
    Signed-off-by: SerenaFeng <feng.xiaowei@zte.com.cn>
  - leverage data_files to eliminate so many hardcoded abs_path_seekings

    1. mv conf/ userconfig/ compliance/ patch to etc/
    2. after installation etc/ will be put under /etc/dovetail
    3. leveraging /etc/dovetail in coding

    Change-Id: Icf9cb00ff7fc7cf35755f60d3e258b23e2c70839
    Signed-off-by: SerenaFeng <feng.xiaowei@zte.com.cn>

diff --git a/docs/submodules/dovetail b/docs/submodules/dovetail
index c308b9a..ead4a2b 160000 (submodule)
--- a/docs/submodules/dovetail
+++ b/docs/submodules/dovetail
@@ -1 +1 @@
-Subproject commit c308b9a718b8b4fc5e781f8d2a6dbe714e381834
+Subproject commit ead4a2bee15cf8c5891497c23592f8fa4fc2dc91