Update git submodules

* Update docs/submodules/yardstick from branch 'master'
  - Merge "tc_heat_rfc2544_ipv4_1rule_1flow_64B_trex.yaml updated"
  - tc_heat_rfc2544_ipv4_1rule_1flow_64B_trex.yaml updated

    Change-Id: Ie9cee3e0567e771cbf11a9802bd33a420cc1ee7a
    Signed-off-by: Ross Brattain <ross.b.brattain@intel.com>

diff --git a/docs/submodules/yardstick b/docs/submodules/yardstick
index e2d429a..0420400 160000 (submodule)
--- a/docs/submodules/yardstick
+++ b/docs/submodules/yardstick
@@ -1 +1 @@
-Subproject commit e2d429a753b9e97fa4744fecf8a6a13c51b259b5
+Subproject commit 04204005faedc1b8eab88d4950b65c710efc11d0