Update git submodules

* Update docs/submodules/yardstick from branch 'stable/fraser'
  - Merge "Make security group configurable - dovetail" into stable/fraser
  - Make security group configurable - dovetail

    Make sercurity group can be configured via the context.
    The format would be:
    context:
      name: demo
      image: yardstick-image
      flavor: yardstick-flavor
      user: ubuntu
      security_group:
        rules:
            - remote_ip_prefix: "0.0.0.0/0"
              protocol: "tcp"
              port_range_min: 1
              port_range_max: 65535
            - remote_ip_prefix: "0.0.0.0/0"
              protocol: "udp"
              port_range_min: 1
              port_range_max: 65535
            - remote_ip_prefix: "0.0.0.0/0"
              protocol: "icmp"

    JIRA: YARDSTICK-1360

    Change-Id: I00c45767ee2d70b790590e824599d5a4c274bced
    Signed-off-by: rexlee8776 <limingjiang@huawei.com>
    (cherry picked from commit cea576574ac0554c1320179bffe6965ac1333972)

diff --git a/docs/submodules/yardstick b/docs/submodules/yardstick
index 583464e..a0cae34 160000 (submodule)
--- a/docs/submodules/yardstick
+++ b/docs/submodules/yardstick
@@ -1 +1 @@
-Subproject commit 583464e18daf70712ab5c7e4763674c176ebbd81
+Subproject commit a0cae34ea1515654309c9d18419ac0caf4c6e5c6