Add simple console testing harness for expected output. This allows us
to validate that the test is running properly on hardware.
We expect the sample to report back somthing like:
Counter received: 1
Counter received: 2
Counter received: 3
Counter received: 4
...
etc.
So have a simple regex check for it.
Signed-off-by: Kumar Gala <kumar.gala@linaro.org>