Update git submodules

Update git submodules

* Update docs/submodules/yardstick from branch 'master'
  - Merge "NSB Prox BM test case fixes for scale up"
  - NSB Prox BM test case fixes for scale up

    YARDSTICK-839

    In a scale-up test the VNF number can start from
    0 to MAX (num_vnf-1)

    The NSB PROX BM test nodes are currently marked as:
        tg__0: trafficgen_1.yardstick
        vnf__0: vnf.yardstick
    They need to be changed to the below:
        tg__0: tg_0.yardstick
        vnf__0: vnf_0.yardstick

    Changes done are:
    - All BM Prox test cases have tg_0 and vnf_0 as default
      test nodes
    - The prox-baremetal-1/2/4.yaml sample pod file
    - Cleaned Up some unused Prox test/config files

    Change-Id: I819011bcb35eda62b17dd3e1035918918c582b13
    Signed-off-by: Abhijit Sinha <abhijit.sinha@intel.com>