Update git submodules

Update git submodules

* Update docs/submodules/releng-xci from branch 'master'
  - Merge "Integrate ceph in XCI"
  - Integrate ceph in XCI

    Openstack ansible support to deploy ceph.
    The purpose of this patch is to configure the ceph,
    just like we configure other openstack components.

    The default is to not deploy ceph.
    If you want to deploy ceph you just need to
    export XCI_CEPH_ENABLED=true before running xci-deploy.sh.
    When deployed successfully, the openstack storage will use ceph.

    Change-Id: Ifd8d16fdce2914b6316842e72bbfd93228ea059d
    Signed-off-by: wutianwei <wutianwei1@huawei.com>