Fix timer 1 interrupts
HAL timer 1 interrupts were never being enabled, and use of an uninitialised register in HAL_TimerIRQClear meant it was potentially clearing both interrupts instead of just one of them.
HAL timer 1 interrupts were never being enabled, and use of an uninitialised register in HAL_TimerIRQClear meant it was potentially clearing both interrupts instead of just one of them.