Update git submodules

* Update docs/submodules/yardstick from branch 'stable/danube'
  - Merge "Add CPU pinning support for node context" into stable/danube
  - Add CPU pinning support for node context

    JIRA: YARDSTICK-573

    Since the yardstick framework now has supported an improved node type context,
    this patch adds support for VM vcpu pinning ability in the node type context.
    It provides several scripts that can be used to configurate the controller and
    compute nodes.

    Change-Id: If2c6e7b1b85ff78b9d2a5997bf03bdc6877aaf74
    Signed-off-by: JingLu5 <lvjing5@huawei.com>
    (cherry picked from commit f138b480ea4c9954d107555d7a46ec3d4375653f)

diff --git a/docs/submodules/yardstick b/docs/submodules/yardstick
index 87ad2e4..c97a190 160000 (submodule)
--- a/docs/submodules/yardstick
+++ b/docs/submodules/yardstick
@@ -1 +1 @@
-Subproject commit 87ad2e4366889f835d7608c88990cba12013f4c4
+Subproject commit c97a1907549f841cc5b2d2efeacea7c703b0de3f