Update git submodules

* Update docs/submodules/yardstick from branch 'master'
  - add release date

    Change-Id: Icf12b7a59144754f65f67ed54a5c455a64c5042f
    Signed-off-by: Ross Brattain <ross.b.brattain@intel.com>

diff --git a/docs/submodules/yardstick b/docs/submodules/yardstick
index 9449bbf..9210493 160000 (submodule)
--- a/docs/submodules/yardstick
+++ b/docs/submodules/yardstick
@@ -1 +1 @@
-Subproject commit 9449bbf4608d74da8cf61cb4178c844a0095f78f
+Subproject commit 92104932aa57b703d86926fc3aad13d742a41652