Update git submodules

* Update docs/submodules/releng from branch 'master'
  - Exposes GERRIT_REFSPEC parameter to build

    This value is usually passed by parent jobs (daily, verify, etc), but
    exposing it as parameter should allow us to build from JJB GUI.

    Change-Id: I294fbcd200ff5d8bbfca77681296c6e59d7f0063
    Signed-off-by: Tim Rozet <trozet@redhat.com>

diff --git a/docs/submodules/releng b/docs/submodules/releng
index aae2c9f..5ceb80c 160000 (submodule)
--- a/docs/submodules/releng
+++ b/docs/submodules/releng
@@ -1 +1 @@
-Subproject commit aae2c9fc13bb2ec28afc7500ba4a1ecd0db9cddd
+Subproject commit 5ceb80c42816fea021fdf7abe154a4709294d4a3