Update git submodules

* Update docs/submodules/armband from branch 'master'
  - bootstrap, dea_base, nailgun: Pin 4.8.0-9944 krn

    New kernel includes:
    - ABI bump;
    - GICv3-ITS live migration support;

    TODO: build meta package so we don't have to bump it manually.

    JIRA: ARMBAND-171

    Change-Id: I4aaa5ca496e535abed948d2e51a6caf7e03393a8
    Signed-off-by: Alexandru Avadanii <Alexandru.Avadanii@enea.com>

diff --git a/docs/submodules/armband b/docs/submodules/armband
index 6b5e1a9..06a8e92 160000 (submodule)
--- a/docs/submodules/armband
+++ b/docs/submodules/armband
@@ -1 +1 @@
-Subproject commit 6b5e1a9bc6c1f260e15e0f5698382d8feb992caa
+Subproject commit 06a8e925413c3ed0019c714eb83dab2ae179d641