Update git submodules

* Update docs/submodules/yardstick from branch 'master'
  - Merge "Update samples/test_suite.yaml"
  - Update samples/test_suite.yaml

    The sample test suite at sample/test_suite.yaml contained incorrect
    syntax. It has been updated to add the "default" parameter to
    "task_args" when running a testcase.

    JIRA: YARDSTICK-1125
    Change-Id: I53409168e47d969317145623df1e2c789396cc32
    Signed-off-by: Emma Foley <emma.l.foley@intel.com>

diff --git a/docs/submodules/yardstick b/docs/submodules/yardstick
index 4cde902..d5f2224 160000 (submodule)
--- a/docs/submodules/yardstick
+++ b/docs/submodules/yardstick
@@ -1 +1 @@
-Subproject commit 4cde90255da477f4cd942a024e44426285f0c9ca
+Subproject commit d5f2224309dcefa2acd3bb3bb822ce9379c0ecbc