Update git submodules

Update git submodules

* Update docs/submodules/clover from branch 'stable/gambia'
  - Merge "Initial commit of controller services config guide" into stable/gambia
  - Initial commit of controller services config guide

    - Controller services lump cloverctl CLI and clover-controller
    together and this config guide provides brief overview
    and deploy/delete instructions
    - Intended to be one of the first guides a user follows,
    as controller is prerequisite for many other Clover services
    - Add new, existing config guides to index
    including forthcoming jmeter, visibility guides
    - Embedded images forthcoming

    Change-Id: Ifef0248d9370df862a1d192b979606e443a82e95
    Signed-off-by: earrage <eddie.arrage@huawei.com>