Update git submodules

* Update docs/submodules/yardstick from branch 'master'
  - Merge "update docs for procedure after host reboot"
  - update docs for procedure after host reboot

    Added instructions to restart nginx and uwsgi after the host is rebooted.
    Added instructions to start yardstick container if the host is rebooted.
    Removed section on virtual python environment as it is not needed.

    JIRA: YARDSTICK-919

    Change-Id: I6e8bd1d52954c2aa138ce7879211b91b3644ecb2
    Signed-off-by: John O Loughlin <john.oloughlin@intel.com>

diff --git a/docs/submodules/yardstick b/docs/submodules/yardstick
index 3778448..7905760 160000 (submodule)
--- a/docs/submodules/yardstick
+++ b/docs/submodules/yardstick
@@ -1 +1 @@
-Subproject commit 377844823ff4913f2cf94ce27eb51a82436cbbe9
+Subproject commit 7905760496227384c56f143ca338529d7783b18b