Update git submodules

* Update docs/submodules/yardstick from branch 'master'
  - Merge "Update the traffic profile to support sample multi-port"
  - Update the traffic profile to support sample multi-port

    Change-Id: Iaf8b3e0aa3855443b0628573a1df98d177f27c76
    Signed-off-by: Deepak S <deepak.s@linux.intel.com>

diff --git a/docs/submodules/yardstick b/docs/submodules/yardstick
index b346b40..c270be4 160000 (submodule)
--- a/docs/submodules/yardstick
+++ b/docs/submodules/yardstick
@@ -1 +1 @@
-Subproject commit b346b40f67feb1a38226be12f0d57a6bf6f8a2fe
+Subproject commit c270be42cde9e26018809fef35e401729be77eb1