Update git submodules

* Update docs/submodules/releng from branch 'master'
  - Merge "Rename odl_l3 to odl"
  - Rename odl_l3 to odl

    Rename all scenarios with "odl_l3" in their name in Euphrates to
    just "odl".

    Change-Id: If2bff0da79f79b9305771d2fc575db1606cd4bf9
    Signed-off-by: Zhijiang Hu <hu.zhijiang@zte.com.cn>

diff --git a/docs/submodules/releng b/docs/submodules/releng
index be3f797..9b51caa 160000 (submodule)
--- a/docs/submodules/releng
+++ b/docs/submodules/releng
@@ -1 +1 @@
-Subproject commit be3f797263efd68c1b2258719b60457937f910e0
+Subproject commit 9b51caad5c0f30a7e8f9828024b548d457ae4128