Update git submodules

* Update docs/submodules/yardstick from branch 'master'
  - Removed special networking from yardstick container when started by nsb_setup.

    Change-Id: Ief1cfd7c018948a9125549400bb5bf0e5c20d730
    Signed-off-by: Maciej Skrocki <maciej.skrocki@intel.com>

diff --git a/docs/submodules/yardstick b/docs/submodules/yardstick
index 2430ee2..53a55a8 160000 (submodule)
--- a/docs/submodules/yardstick
+++ b/docs/submodules/yardstick
@@ -1 +1 @@
-Subproject commit 2430ee2bbede7c26f50883ed3bf8d2ab92f9c66b
+Subproject commit 53a55a8e95ad31ef6af0978e871092ddeb2dc597