Update git submodules

* Update docs/submodules/releng from branch 'master'
  - Merge "Create Gambia branch for Edge Cloud Project"
  - Create Gambia branch for Edge Cloud Project

    Creation of the Gambia stable branch for the edge cloud project

    JIRA: EDGE-1

    Change-Id: I87c787a5abfc82f6e71c55fb1593836dd86ef2c8
    Signed-off-by: fuqiao@chinamobile.com
    Signed-off-by: Trevor Bramwell <tbramwell@linuxfoundation.org>

diff --git a/docs/submodules/releng b/docs/submodules/releng
index 0f1dd55..e814256 160000 (submodule)
--- a/docs/submodules/releng
+++ b/docs/submodules/releng
@@ -1 +1 @@
-Subproject commit 0f1dd553c8746775b6eb87996854e4a8ff7515cd
+Subproject commit e81425675f6c9270b805c3235d08752941ef3049