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>

diff --git a/docs/submodules/yardstick b/docs/submodules/yardstick
index 0b21b64..a6adb45 160000 (submodule)
--- a/docs/submodules/yardstick
+++ b/docs/submodules/yardstick
@@ -1 +1 @@
-Subproject commit 0b21b6484cc383f2a78aa9d5db1d41189d84ca3d
+Subproject commit a6adb45bb0ee22f2548004afe0d8a7b09e7c15c4