Update git submodules

* Update docs/submodules/releng from branch 'master'
  - Merge "Integrate functest with ARM Architecture with alpine images"
  - Integrate functest with ARM Architecture with alpine images

    Read compute architecture form salt master and send it as
    environment variable.
    JIRA: ARMBAND-310

    Change-Id: I5c44697d1856f4d09df6fbbbf23ec94478e08f21
    Signed-off-by: Delia Popescu <delia.popescu@enea.com>

diff --git a/docs/submodules/releng b/docs/submodules/releng
index 1428827..a4c213d 160000 (submodule)
--- a/docs/submodules/releng
+++ b/docs/submodules/releng
@@ -1 +1 @@
-Subproject commit 1428827b25bec913979c9c3f85672668a0b1961c
+Subproject commit a4c213d48688fba421c0e380c0f96978589af501