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).
"malloc" test is used a simple thread that executes only malloc and free, but it seems that there is a difference in the stack used between Cortex-A and Cortex-M.
As a result of check, in Cortex-A, program aborts because of the lack of stack when THREAD_STACK_SIZE is 256, workes properly when THREAD_STACK_SIZE is 512 at least. Since it seems that the definition processing of "DEFAULT_STACK_SIZE" was gone from Mbed OS by updating CMSIS5/RTX5, I setted 512 directly for Cortex-A.
Reduce RAM consumption so all tests can still be built when using
CMSIS/RTX5. Also reduce clutter by removing the per target stack size
defines in the tests.