Update git submodules

* Update docs/submodules/releng from branch 'master'
  - Functest: Restores ability to run with pre-defined creds

    This patch is needed for the case where there are provided OS
    credentials to functest, and there is no need to find the installer VM
    and copy the credentials to the host. In the Apex snapshot case, there
    is no installer VM on the slave, so we must provide the credentials
    file.

    Also includes a fix to use tempest_smoke_serial for the snapshot netvirt
    verification until CSIT suite is working correctly.

    Change-Id: Ic84955f527e3f84bb0d8579a377b4a1883fe3eb2
    Signed-off-by: Tim Rozet <trozet@redhat.com>

diff --git a/docs/submodules/releng b/docs/submodules/releng
index 0f9c8ce..bef419d 160000 (submodule)
--- a/docs/submodules/releng
+++ b/docs/submodules/releng
@@ -1 +1 @@
-Subproject commit 0f9c8ced437af4cae8b25387142bec5d42fab138
+Subproject commit bef419de784f2684a431598e6566f2b81d01cb8e