Update git submodules

Update git submodules

* Update docs/submodules/dovetail from branch 'master'
  to 418cce60e12698b0a4d1c4518070cf290a9f6581
  - Add License

    Many files in Dovetail repo are lacking of License after LF scanning.
    Add all of them except the following files:
    1. docker/Dockerfile.aarch64.patch
    2. 0001-Allow-additional-properties-in-API-responses.patch
    3. docs/images/dovetail_offline_mode.xcf
    4. docs/images/dovetail_onfline_mode.xcf
    5. all png files
    6. all empty files

    Change-Id: If1a0b7c2d35d6682c87c4eb9106e1998dc4ca3bc
    Signed-off-by: xudan <xudan16@huawei.com>