Correct timebase_ms after deep sleep

During deep sleep, the millisecond counter is stopped. To ensure correct delay
times, we add the sleep duration to the counter after wakeup.

src/main.c

@@ -379,6 +379,9 @@ int main(void)
 						if((timebase_ms - charge_control_idle_since) > FLASH_CONFIG_DEEPSLEEP_DELAY) {
 							low_power_mode(FLASH_CONFIG_DEEPSLEEP_DURATION);
 							charge_control_was_idle = false;
+
+							// correct the time base after deep sleep
+							timebase_ms += FLASH_CONFIG_DEEPSLEEP_DURATION * 1000;
 						}
 					}
 				} else {