Update git submodules

* Update docs/submodules/yardstick from branch 'master'
  - Merge "Assign static IP to VM for standalone context"
  - Assign static IP to VM for standalone context

    During VM spawning IP address should be assigned by DHCP server in
    the local network. Sometimes DHCP server is not capable to assign IP
    address. So, need to add static IP address.

    JIRA: YARDSTICK-1402

    Change-Id: Ie59c340eb88eddcaff043496fc20aa48b49205ec
    Signed-off-by: Stepan Andrushko <stepanx.andrushko@intel.com>

diff --git a/docs/submodules/yardstick b/docs/submodules/yardstick
index 680de98..4e2e9eb 160000 (submodule)
--- a/docs/submodules/yardstick
+++ b/docs/submodules/yardstick
@@ -1 +1 @@
-Subproject commit 680de98b5f0e63fecb795de128448859bd231b6a
+Subproject commit 4e2e9ebce2eb642480af80cdb63d442dfb81cd04