Fix GPS nav epoch recovery and document debug levels

soc/software/gps_system/header/gps/gps_nav_epoch.h

@@ -35,7 +35,7 @@ typedef enum {
 	GPS_NAV_EPOCH_EVENT_ACCEPTED,
 	GPS_NAV_EPOCH_EVENT_DUPLICATE,
 	GPS_NAV_EPOCH_EVENT_STALE,
-	GPS_NAV_EPOCH_EVENT_FUTURE,
+	GPS_NAV_EPOCH_EVENT_RESTARTED,
 	GPS_NAV_EPOCH_EVENT_COMPLETE
 } gps_nav_epoch_event_result_t;