Update git submodules

* Update docs/submodules/yardstick from branch 'master'
  - Increase timeouts for installing requrements

    Currently the docker images fails to build on aarch64 because the installation
    of the requirements step fails. The failure is caused by the timers which expire
    and don't mark the job as finished.

    JIRA: ARMBAND-391

    Change-Id: Ic84982f81d064af1c27cf776d12a57eadc20957a
    Signed-off-by: Cristina Pauna <cristina.pauna@enea.com>

diff --git a/docs/submodules/yardstick b/docs/submodules/yardstick
index caee6b2..3a67d33 160000 (submodule)
--- a/docs/submodules/yardstick
+++ b/docs/submodules/yardstick
@@ -1 +1 @@
-Subproject commit caee6b2a603388c02e961582d78244a2e9e98372
+Subproject commit 3a67d335d32ba460033ba042c1dd66ea2ab852a1