Update git submodules

Update git submodules

* Update docs/submodules/dovetail from branch 'master'
  - Merge "Add test area 'forwarding packets through virtual networks in data path'"
  - Add test area 'forwarding packets through virtual networks in data path'

    JIRA: DOVETAIL-473

    According to Dovetail addendum doc, add one test area about basic cloud
    capability 'forwarding packets through virtual networks in data path'.

    Add the test specification about this test area.

    Change-Id: I26416ecca6b89a94cf48ba0f55308df0fa6e1677
    Signed-off-by: xudan <xudan16@huawei.com>