Update git submodules

Update git submodules

* Update docs/submodules/compass4nfv from branch 'stable/danube'
  - Add opendaylight sfc support for compass installer

    JIRA: COMPASS-483

    As odl sfc has been supported by other installers,
    we compass project has also support odl boron and tacker now.
    So we are going to support odl sfc+tacker in Danube release.

    This patch includes:

    1. Add ovs-common and ovs-dkms
    2. Install networking-sfc for neutron and odl
    3. Configure odl sfc in neutron ml2
    4. Add sfc related features in odl
    5. Add sfc related repo making scripts
    6. Add odl_sfc switch both in compass4nfv and compass-core

    Change-Id: If37a9e190c3095d771ffab61777a927b6d94ea9e
    Signed-off-by: Yifei Xue <xueyifei@huawei.com>