Build Timeout Wrapper for Yardstick

Build Timeout Wrapper for Yardstick

Yardstick builds are hanging and not being caught for 19+ hours. Using
the build timeout plugin we should be able to quickly stop these builds
and let the project know much sooner there is an issue with their
builds.

The default timeout is set to fail if the job takes longer than 30 minutes.
This can be adjusted later if the time is too long or too short.

ssh-agent-wrapper is included as it is the default from globals, and
defaults are superceded by fields added to jobs.

Change-Id: I9529ab7b6ab8819ceb91694fefbb4ecb3f5cf81c
Signed-off-by: Trevor Bramwell <tbramwell@linuxfoundation.org>