Update git submodules

* Update docs/submodules/armband from branch 'master'
  - AArch64 NIC adaptation patch

    AArch64 NIC adaptation for dual NIC boards with traffic separation
     -kvm nodes: added second trunk_nic
     -compute nodes: removed third external_nic

    Change-Id: I874094075ab01c7fe21af26602a7366a371cec28
    Signed-off-by: Guillermo Herrero <guillermo.herrero@enea.com>

diff --git a/docs/submodules/armband b/docs/submodules/armband
index 8ac5a46..e726054 160000 (submodule)
--- a/docs/submodules/armband
+++ b/docs/submodules/armband
@@ -1 +1 @@
-Subproject commit 8ac5a461c90545aa06538f5376cc929b2297f19a
+Subproject commit e7260544c63bfd1e52a52839ad6527b0bc2ce75d