Update git submodules

* Update docs/submodules/releng from branch 'master'
  - [fuel, armband] Disable aarch64 verify jobs

    Our hardware does not support nested virtualization on aarch64, so
    our verify jobs cannot run any real tests that require spawning VMs
    on a virtual POD, where all verify jobs were previously scheduled.

    So all aarch64 verify jobs used to be limited to checking that the
    Armband patches apply cleanly on top of OPNFV Fuel. Now that all
    Armband patches are upstream in OPNFV Fuel, the verify jobs became
    more or less a no-op, so let's just disable them.

    Change-Id: Ibe86f58978c961e221c90ccb8b2666598981f464
    Signed-off-by: Alexandru Avadanii <Alexandru.Avadanii@enea.com>

diff --git a/docs/submodules/releng b/docs/submodules/releng
index 1d106b0..c6d685a 160000 (submodule)
--- a/docs/submodules/releng
+++ b/docs/submodules/releng
@@ -1 +1 @@
-Subproject commit 1d106b04c6294905b85c25bd4542b3aded638eb8
+Subproject commit c6d685aa45e14d181c48b98d84eb6eb74ccc3215