timer: support terminate of timer
timer: support terminate of timer

Currently, there is no way to stop the this example. Therefore,
have to wait until the timer test is finished. This commit adds
the way to stop the timer.

Change-Id: I1f9ac9191e08fd2815877699d05c8413d6093b64
Signed-off-by: Jihun Ahn <31fe625dd60d1475d1b18ea57157c450e67c870a@samsung.com>

JunhwanPark/TizenRT,JunhwanPark/TizenRT,JunhwanPark/TizenRT,JunhwanPark/TizenRT,JunhwanPark/TizenRT,JunhwanPark/TizenRT