Update git submodules

Update git submodules

* Update docs/submodules/releng-xci from branch 'master'
  - Nomination of Periyasamy Palanisamy as XCI committer

    Periyasamy Palanisamy onboarded SDNVPN project to XCI,
    contributed various scenarios and made contributions to upstream
    projects.

    His contributions include
    - creating os-odl-nofeature scenario
    - integrating ovs into os-nosdn-nofeature scenario
    - creating os-odl-bgpvpn scenario
    - improving the framework
    - reviewing changes

    His contributions can be seen from following link:
    https://gerrit.opnfv.org/gerrit/#/q/owner:periyasamy.palanisamy%2540ericsson.com+project:releng-xci+status:merged

    Apart from contributing to XCI, he directly worked in upstream for
    integrating different features and improving things. Some of his
    contributions can be seen from following links:
    https://review.openstack.org/#/q/owner:%22Periyasamy+Palanisamy+%253Cperiyasamy.palanisamy%2540ericsson.com%253E%22+status:merged
    https://git.opendaylight.org/gerrit/#/q/project:integration/packaging/ansible-opendaylight+owner:periyasamy.palanisamy%2540ericsson.com+status:merged

    Change-Id: I1b86938b8519e758801339fb8029f8b2dd1f7918
    Signed-off-by: Fatih Degirmenci <fdegir@gmail.com>