Update git submodules

* Update docs/submodules/releng from branch 'master'
  - Merge "Set image and flavor env variables functest for ovs|fdio"
  - Set image and flavor env variables functest for ovs|fdio

    Set IMAGE_PROPERTIES and FLAVOR_EXTRA_SPECS environment variables
    for functest CI run for ovs and fdio scenarios.

    Change-Id: Ib2be311ee28d4ae633ec5496a12e741f701cc7ab
    Signed-off-by: Delia Popescu <delia.popescu@enea.com>

diff --git a/docs/submodules/releng b/docs/submodules/releng
index dc9acb2..9f2107e 160000 (submodule)
--- a/docs/submodules/releng
+++ b/docs/submodules/releng
@@ -1 +1 @@
-Subproject commit dc9acb20964cae37e5fd197984233c5614d4990d
+Subproject commit 9f2107eb7569697a77f74cec6894637318e0fac7