Update git submodules

Update git submodules

* Update docs/submodules/releng from branch 'master'
  - xci: Yet another try to find how best to structure stuff

    Summary of changes are
    - flavors directory has been removed and the flavor config files are
    moved into config and renamed to <flavor>-vars
    - common files are put under file
    - files specific to flavors are put under file/<flavor> directories
    - templates and var files are stored in template and var directories
    respectively
    - 3 playbooks are created

    Change-Id: I8a93e0947ccb02f93a6c8f00da27e0cc6b4dc21e
    Signed-off-by: Fatih Degirmenci <fatih.degirmenci@ericsson.com>