Update git submodules

Update git submodules

* Update docs/submodules/fuel from branch 'stable/euphrates'
  - Merge "Update opendaylight/neutron patch" into stable/euphrates
  - Update opendaylight/neutron patch

    Align opendaylight support patch with latest neutron formula.
    Employ native ML2 backend/engine option as is instead of bringing
    in the "opendaylight" keyword into reclass model.
    Unfreeze the maas & neutron formulas versions.

    Change-Id: I2807dcf9f83b01d453bca6453524f840c378972f
    Signed-off-by: Michael Polenchuk <mpolenchuk@mirantis.com>
    (cherry picked from commit 1a8153f6391bdde1bab21f7831841f5b6070832d)