Update git submodules

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>