Timer application (app/timer-app.c)

Application demonstrates the timer driver APIs and uses timer2 in 5 seconds periodic mode.

The ENABLE_TIMER_APP flag in the soc/*/target_specific.mk file controls compilation of this demo app.

When the app successfully executes, it displays the following message at every TIMER2_PTV seconds

Timer2 irq triggered

Additionally, it calls the timer stop API after the count value reaches STOP_TIMER.