Update git submodules

* Update docs/submodules/armband from branch 'master'
  - p/fuel: lib.sh: Revert to virtio-mmio for PXE net

    virtio-pci-net seems to have issues with more than three (3)
    interfaces attached to the same guest, even on separate PCI buses.

    To bypass this limitation, for now, we will use virtio-mmio for
    PXE, and virtio-pci-net for the rest.

    This keeps the guest eth order consistent and predictable, and
    allows udev to assign predictable interface names for 3 out of 4
    guest network interfaces (enp2sX), thus ensuring PXE will always
    get the "eth0" designator.

    Change-Id: I0d0cb8148cd87313e67f8f27793eb2414c1e90e3
    Signed-off-by: Alexandru Avadanii <Alexandru.Avadanii@enea.com>

diff --git a/docs/submodules/armband b/docs/submodules/armband
index 66e14ec..4f72e6b 160000 (submodule)
--- a/docs/submodules/armband
+++ b/docs/submodules/armband
@@ -1 +1 @@
-Subproject commit 66e14ec7a5a480d11467e604d76615daa92bb527
+Subproject commit 4f72e6be436badd2ded546424ec4a304cd6ce5d3