Update git submodules

* Update docs/submodules/releng from branch 'master'
  - Functest, Yardstick, Apex: Fix missing jobs

    Functest/yardstick jobs are missing for Gambia. This patch
    adds them.

    Change-Id: If65bc5927dba745ff5dbd858b4e612c0f48e1ab1
    Signed-off-by: Tim Rozet <trozet@redhat.com>

diff --git a/docs/submodules/releng b/docs/submodules/releng
index 86c90b0..2646bc6 160000 (submodule)
--- a/docs/submodules/releng
+++ b/docs/submodules/releng
@@ -1 +1 @@
-Subproject commit 86c90b040528241792a4f54430bb42ad17fcbdd5
+Subproject commit 2646bc657d1615f7f7131e824fc4bf7a8e1692df