Update git submodules

Update git submodules

* Update docs/submodules/yardstick from branch 'stable/gambia'
  - Merge "Dashboard with Network and Platform NFVi metrics" into stable/gambia
  - Dashboard with Network and Platform NFVi metrics

    Added the PROX L3FWD Grafana dashboard with NFVi metrics
    collected from barometer collectd container.

    The dashboard has template field for HOST/SUT name
    to get the collectd metrics from that SUT.

    JIRA: YARDSTICK-1412

    Update:
    - Added table and graphs for TG NFVi metrics
    - Added TG and SUT templates as IP address
    - Added IPC(instruction per cycles) metric

    Change-Id: I1f8971f551df27ad6a16241693527285610fc82d
    Signed-off-by: Abhijit Sinha <abhijit.sinha@intel.com>
    (cherry picked from commit e63084495f47a9f5b5b61b23529792d6898841bb)