Since target specific ticker drivers are not ready also features which uses ticker in upper layers may not work correctly and tests for these features.
We need to disable also failing higher level ticker related tests (by adding check if DEVICE_USTICKER symbol is available and raise #error [NOT_SUPPORTED] if not).
In the 'Testing accuracy of equeue semaphore' test case result is printed out in each loop iteration.
Since debug prints should not exist in the final test version I suggest to print information only in case of failure.
Additionally time needed to print single info is equal to ~25 ms (K64F/GCC_ARM). The while loop is designed to execute until 20000 ms elapses, so this print has also impact on number of times the loop is executed (number of semaphore accuracy checks).
A units mistake led to passing 20000 seconds instead of 20000 milliseconds
to greentea. The would cause the test to spin for 6 hours if it got stuck
anywhere.