Update git submodules

* Update docs/submodules/releng from branch 'master'
  - Merge "fuel-armband: Add functest and yardstick as downstream jobs"
  - fuel-armband: Add functest and yardstick as downstream jobs

    Change-Id: I003f760adc2cb0b4959188b7f7d676d8fdbd8bb9
    Signed-off-by: Fatih Degirmenci <fdegir@gmail.com>

diff --git a/docs/submodules/releng b/docs/submodules/releng
index 2f19334..588a3ff 160000 (submodule)
--- a/docs/submodules/releng
+++ b/docs/submodules/releng
@@ -1 +1 @@
-Subproject commit 2f193344d484554e3988ad18cfb467683250f57b
+Subproject commit 588a3ff5cd44a212c3ba3ec8bba2cdee24b50a87