Update git submodules

Update git submodules

* Update docs/submodules/releng-xci from branch 'master'
  - Merge "Ensure XCI_DEVEL_ROOT is removed"
  - Ensure XCI_DEVEL_ROOT is removed

    It is important to start with a clean XCI_DEVEL_ROOT in order to
    ensure the leftovers from the previous deployment doesn't result
    in successful or failed deployments due to not having it in sync
    with the latest updates.

    Change-Id: I00d77e1fc62cccda7920af3469af9d44247780f4
    Signed-off-by: Fatih Degirmenci <fatih.degirmenci@ericsson.com>