stm32/stm32_it: Fix RTC IRQ handler to handle all EXTI IRQs on F0 MCUs.

ports/stm32/stm32_it.c

@@ -509,8 +509,18 @@ void RTC_WKUP_IRQHandler(void) {
 
 void RTC_IRQHandler(void) {
     IRQ_ENTER(RTC_IRQn);
+    if (RTC->ISR & RTC_ISR_WUTF) {
         RTC->ISR &= ~RTC_ISR_WUTF; // clear wakeup interrupt flag
         Handle_EXTI_Irq(EXTI_RTC_WAKEUP); // clear EXTI flag and execute optional callback
+    }
+    if (RTC->ISR & RTC_ISR_ALRAF) {
+        RTC->ISR &= ~RTC_ISR_ALRAF; // clear Alarm A flag
+        Handle_EXTI_Irq(EXTI_RTC_ALARM); // clear EXTI flag and execute optional callback
+    }
+    if (RTC->ISR & RTC_ISR_TSF) {
+        RTC->ISR &= ~RTC_ISR_TSF; // clear timestamp flag
+        Handle_EXTI_Irq(EXTI_RTC_TIMESTAMP); // clear EXTI flag and execute optional callback
+    }
     IRQ_EXIT(RTC_IRQn);
 }