Update git submodules

Update git submodules

* Update docs/submodules/yardstick from branch 'master'
  - NSB: remove validate_cpu_cfg and all app cpu methods

    We don't really know what core we are going to use for the
    VNF before we generate the MultiPortConfig, so these
    methods are incorrect.

    We may need some more advanced method to validate
    the vCPU topology, but that will probably happen
    in the MultiPortConfig

    Change-Id: Ifee7ae4589ce0fce67771fb8d8b8dce0a0f06409
    Signed-off-by: Ross Brattain <ross.b.brattain@intel.com>