Update git submodules

Update git submodules

* Update docs/submodules/fuel from branch 'master'
  - [AArch64] Pin armband repo with highest prio

    Mirantis repositories shadow certain packages from Armband repos
    (e.g. qemu-efi) if pinning is not set.
    Since MaaS does not allow configuring repo priorities via its API,
    use Salt pillar data to re-define the Armband repo and set its prio.

    Change-Id: Ic743f4b684b3f13552792f5f04097fac73171b37
    Signed-off-by: Alexandru Avadanii <Alexandru.Avadanii@enea.com>