This test works by starting a bunch of poll events, dropping the test
thread priority, calling k_poll(), and assuming that all the timeouts
that fired woke up high priority threads and thus ran before k_poll()
could return. But that isn't true if you have another CPU that can
run the low priority thread while the last high priority thread
finishes up!
This just isn't SMP-correct. Mark 1cpu.
Signed-off-by: Andy Ross <andrew.j.ross@intel.com>