Update git submodules

Update git submodules

* Update docs/submodules/dovetail from branch 'master'
  - Merge "Support to run mandatory or optional test cases separately"
  - Support to run mandatory or optional test cases separately

    1. Currently, dovetail can run a test suite or a test area in that test suite.
    2. The test areas in one test suite are not divided into optional and mandatory.
    3. Split them and support to run just mandatory or optional.
    4. Support to run multiple test areas.

    JIRA: DOVETAIL-505

    Change-Id: I42cd7b4e11c3e3674c806e9bc999b782bf5c85c6
    Signed-off-by: xudan <xudan16@huawei.com>