Update git submodules

Update git submodules

* Update docs/submodules/dovetail from branch 'master'
  - Merge "AArch64 support for Dovetail docker"
  - AArch64 support for Dovetail docker

    Add aarch64 patch for Dovetail docker file;
    The patch should be applied from releng

    Move to Ubuntu 16.04 in order, since docker.io package was not
    available for arm on Ubuntu 14.04.
    Added "pip install -U setuptools", since installation of other
    components failed because setuptools was missing.

    Change-Id: If00346d89c48be86c6d9b830f75c1792c39d6bb3
    Signed-off-by: Alexandru Nemes <alexandru.nemes@enea.com>