Update git submodules

* Update docs/submodules/releng from branch 'master'
  - Tag Apex for Fraser 6.0

    The last commit I had to revert, as the refs were put under branches
    branch should never change and indicates where the branching happens.

    I have taken those refs and put them in the releases section

    Change-Id: I8026b331b18cde18c08ed1bef79d291c3a7ffce8
    Signed-off-by: agardner <agardner@linuxfoundation.org>

diff --git a/docs/submodules/releng b/docs/submodules/releng
index d454e22..1091916 160000 (submodule)
--- a/docs/submodules/releng
+++ b/docs/submodules/releng
@@ -1 +1 @@
-Subproject commit d454e22c73fea3c97552c880addf6f14868d408b
+Subproject commit 1091916ce1e223d6b4d5ab1fa3c8e3d3c36e08f8