stm32: Fix RTC based tick day change

On starting next calendar day, result of computing time
difference between current time and previous one was negative
and should be corrected by whole day on sub seconds.
It was corrected by one hour instead resulting in
negative tick increment that caused crash at midnight.

This change fixes issue by correcting time difference computation.

hw/mcu/stm/stm32_common/src/hal_os_tick.c

@@ -156,7 +156,8 @@ rtc_update_time(void)
     now = rtc_time_to_sub_seconds(&alarm.AlarmTime);
     delta = now - last_rtc_time;
     if (delta < 0) {
-        delta += 3600 << SUB_SECONDS_BITS;
+        /* Day changed, correct delta */
+        delta += (24 * 3600) << SUB_SECONDS_BITS;
     }
     alarm.AlarmTime.SubSeconds = alarm.AlarmTime.SecondFraction - (now & alarm.AlarmTime.SecondFraction);
     alarm.AlarmTime.SubSeconds -= sub_seconds_per_tick;