Add basic CTRL test

All the CTRL tests were skipped automatically because they were
inherited from before repo split time. This means that MSC CTRL
interface was not tested at all. Add trivial test which uses generic
rate counter introspection so we at least check that MSC's CTRL
interface is not completely broken.

Change-Id: I784feece666b00752a81f2c126e6f255505445be
1 file changed