Update git submodules

* Update docs/submodules/releng from branch 'master'
  - Merge "Create stable/gambia branch for docs"
  - Create stable/gambia branch for docs

    Change-Id: Ib5d5734536869dc08a787ad6624849913b8d5f4b
    Signed-off-by: Sofia Wallin <sofia.wallin@ericsson.com>
    Signed-off-by: Trevor Bramwell <tbramwell@linuxfoundation.org>

diff --git a/docs/submodules/releng b/docs/submodules/releng
index 21d7cee..8b2992c 160000 (submodule)
--- a/docs/submodules/releng
+++ b/docs/submodules/releng
@@ -1 +1 @@
-Subproject commit 21d7cee1df778a802934b659cb63ae14f9e5e27c
+Subproject commit 8b2992ceae90811d0c8f33dd9272aaa215197732