Timer in vibra-module is overwritten in some cases

When doing multiple calls to epic_vibra_vibrate in quick succession, one call might overwrite (by recreating) the timer from the previous call. Testing did not show issues so far, but it might mess with FreeRTOS' internal timer facilities.

Relevant line: vibra.c#L30

It would be better to initialize the timer once and then use xTimerChangePeriod to schedule it. While at it, it might also make sense to convert the timer to a static one by using xTimerCreateStatic instead of xTimerCreate.