Fix IRQ enum protections

Author: hierophect

ports/stm/common-hal/pulseio/PulseIn.c

@@ -133,7 +133,7 @@ void common_hal_pulseio_pulsein_construct(pulseio_pulsein_obj_t* self, const mcu
     self->last_count = 0;
     self->last_overflow = 0;
 
-    if (HAL_TIM_Base_GetState(&tim_handle) == HAL_TIM_STATE_RESET) {
+    if (HAL_TIM_Base_GetState(&tim_handle) == HAL_TIM_STATE_RESET) { //TODO: there's no state yet
         // Find a suitable timer
         TIM_TypeDef * tim_instance = stm_peripherals_find_timer();
         stm_peripherals_timer_reserve(tim_instance);

ports/stm/peripherals/timers.c

@@ -67,7 +67,11 @@ static size_t irq_map[] = {
     NULL_IRQ,
     #endif
     #ifdef TIM6
-    TIM6_DAC_IRQn,
+        #if !defined(DAC_BASE) || !defined(DAC1_BASE)
+        TIM6_IRQn,
+        #else
+        TIM6_DAC_IRQn,
+        #endif
     #else
     NULL_IRQ,
     #endif