Update git submodules

* Update docs/submodules/yardstick from branch 'master'
  - Rabbitmq user fix for collectd

    After rabbitmq server reset we need to setup user profile so that
    collectd and rabbitmq can communitcate. This profile should match amqp
    plugin configuration in collectd.

    Change-Id: I7eef3617d983d909418d484f8ded9e269d5d715d
    Signed-off-by: Dhaval Patel <dhaval.r.patel@intel.com>

diff --git a/docs/submodules/yardstick b/docs/submodules/yardstick
index ad74832..ea8d64b 160000 (submodule)
--- a/docs/submodules/yardstick
+++ b/docs/submodules/yardstick
@@ -1 +1 @@
-Subproject commit ad748320c73587fd09ef7204f03ba3d74567ba78
+Subproject commit ea8d64b33130e75de84f711b04a4eabd32ba75e6