Update git submodules

* Update docs/submodules/yardstick from branch 'master'
  - Yardstick: Aarch64 jenkins slave support

    Change-Id: I2d58c38d75fc1fe036769340e9fb02932f543510
    Signed-off-by: Alexandru Nemes <alexandru.nemes@enea.com>

diff --git a/docs/submodules/yardstick b/docs/submodules/yardstick
index 0367765..241b693 160000 (submodule)
--- a/docs/submodules/yardstick
+++ b/docs/submodules/yardstick
@@ -1 +1 @@
-Subproject commit 0367765435e89f1590c6db25b74880b8014164c8
+Subproject commit 241b693baaec90347d08e63eb1dc167a0033ec21