Skip higher level ticker tests for targets with stale ticker target specific drivers.

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).

Note:
tests-mbed_drivers-rtc is new and uses us ticker to perform a delay.

Author: mprse

TESTS/mbed_drivers/rtc/main.cpp

@@ -21,7 +21,7 @@
 #include "rtos.h"
 #include "rtc_api.h"
 
-#if !DEVICE_RTC
+#if !DEVICE_RTC || !DEVICE_USTICKER
 #error [NOT_SUPPORTED] test not supported
 #endif