Update git submodules

* Update docs/submodules/yardstick from branch 'stable/fraser'
  - Merge "the recovery action of "baremetal down" should be triggered mandatory" into stable/fraser
  - the recovery action of "baremetal down" should be triggered mandatory

    YARDSTICK-1222 has made attacker recover only when the sla not pass.
    But for baremetal down test case, the node need to power on even the sla pass.

    TODO:
    Make attacker can support mandatory recover in some situation.

    JIRA: YARDSTICK-1337

    Change-Id: Ib567b9b9025e5ee421ea47140c468537ad16f090
    Signed-off-by: rexlee8776 <limingjiang@huawei.com>
    (cherry picked from commit 5f11cb9f55aa0529fddfe916a2976a9aa5b4c08f)

diff --git a/docs/submodules/yardstick b/docs/submodules/yardstick
index 3dbd1f3..8af5c09 160000 (submodule)
--- a/docs/submodules/yardstick
+++ b/docs/submodules/yardstick
@@ -1 +1 @@
-Subproject commit 3dbd1f37f5250978ada4e7a0766a949985609e6a
+Subproject commit 8af5c098fb0f30cc1bda0dd4431dbce1b2403a16