Update git submodules

Update git submodules

* Update docs/submodules/releng from branch 'master'
  - Merge "Use docker image id instead of tag to remove yardstick Docker image with tag:<None>"
  - Use docker image id instead of tag to remove yardstick Docker image with tag:<None>

    JIRA: RELENG-194

    Now, in CI, bottlenecks job will pull yardstick Docker image again, which may
    cause the tag of the Docker image previous used by Yardstick changed to 'None'.
    Using 'None' tag to remove Docker image will cause error.

    Change-Id: I5c63c6c515ede5da4f6a40be6bb22fa6771f8f09
    Signed-off-by: JingLu5 <lvjing5@huawei.com>