Fixed setting HardwareTimer interrupt priority

HardwareTimer::setInterruptPriority previously stored the priority fur future use,
but it was typically never applied. It was applied only during the call to
HAL_TIM_Base_Init in the HardwareTimer constructor.

This change sets the priority immediately, in addition to storing it for future use by the HAL.

Author: sjasonsmith

cores/arduino/HardwareTimer.cpp

@@ -35,9 +35,6 @@
 /* Private Variables */
 timerObj_t *HardwareTimer_Handle[TIMER_NUM] = {NULL};
 
-IRQn_Type getTimerUpIrq(TIM_TypeDef *tim);
-IRQn_Type getTimerCCIrq(TIM_TypeDef *tim);
-
 /**
   * @brief  HardwareTimer constructor: set default configuration values
   * @param  Timer instance ex: TIM1, ...
@@ -913,6 +910,10 @@ void HardwareTimer::setPWM(uint32_t channel, PinName pin, uint32_t frequency, ui
   */
 void HardwareTimer::setInterruptPriority(uint32_t preemptPriority, uint32_t subPriority)
 {
+  // Set priority for immediate use
+  NVIC_SetPriority(getTimerUpIrq(_timerObj.handle.Instance), NVIC_EncodePriority(NVIC_GetPriorityGrouping(), preemptPriority, subPriority));
+
+  // Store priority for use if timer is re-initialized
   _timerObj.preemptPriority = preemptPriority;
   _timerObj.subPriority = subPriority;
 }