Update git submodules

* Update docs/submodules/releng from branch 'master'
  - Merge "refactor list operation"
  - refactor list operation

    all operations mix together make it very difficult to read

    Change-Id: I7e4a12fd13a7aa0dc0c8fc09b69c7e43a2ab18ac
    Signed-off-by: SerenaFeng <feng.xiaowei@zte.com.cn>

diff --git a/docs/submodules/releng b/docs/submodules/releng
index 1f0e9dd..efcebb1 160000 (submodule)
--- a/docs/submodules/releng
+++ b/docs/submodules/releng
@@ -1 +1 @@
-Subproject commit 1f0e9ddc87b2259e977463143521448b9ce66945
+Subproject commit efcebb1284264b1f7da4485108f48254aecd0406