Merge pull request #12601 from rajkan01/rtostimer_remove_deprecated

Remove RtosTimer deprecated class

Author: adbridge

TESTS/mbedmicro-rtos-mbed/rtostimer/main.cpp

@@ -20,8 +20,6 @@ Files licensed under MIT:
 - rtos.h
 - rtos_handlers.h
 - rtos_idle.h
-- RtosTimer.cpp
-- RtosTimer.h
 - Semaphore.cpp
 - Semaphore.h
 - ThisThread.cpp