Update git submodules

* Update docs/submodules/yardstick from branch 'master'
  - Merge "Update release note for Danube.3.2"
  - Update release note for Danube.3.2

    Note: This patch should be merger to stable branch.

    Change-Id: I7f07a7c367fc387494f2313143a300fef85a8fd1
    Signed-off-by: JingLu5 <lvjing5@huawei.com>

diff --git a/docs/submodules/yardstick b/docs/submodules/yardstick
index e148db9..0e21cfc 160000 (submodule)
--- a/docs/submodules/yardstick
+++ b/docs/submodules/yardstick
@@ -1 +1 @@
-Subproject commit e148db9421cf04eec7ea117e7c91c27092b2f2bc
+Subproject commit 0e21cfca2c8cd9cf9d06480d0f6e0b8e7535808d