Update git submodules

Update git submodules

* Update docs/submodules/yardstick from branch 'master'
  - Merge "Make Sample VNF hugepages size configurable"
  - Make Sample VNF hugepages size configurable

    The amount of hugepages claimed for a Sample VNF is always 16GB. This
    value is excesive for most of the Sample VNF applications (except for vPE).

    Making this parameter configurable we allow to spawn smaller VMs by using
    less hugepages (in case of StandAlone and OpenStack deployments).

    Because this parameter depends on the Scenario and the type of VNF executed,
    the parameter is located in:

      scenarios: {options: hugepages_gb} # number of GB of hugepages claimed

    PENDING: document this new parameter. A new userguide section should be
             created to document all "scenario" sections and parameters.

    JIRA: YARDSTICK-1061

    Change-Id: I6f082e105289bd01781be18f2fecbe0ba2fdfdee
    Signed-off-by: Rodolfo Alonso Hernandez <rodolfo.alonso.hernandez@intel.com>