Keep fused location streaming through GPS rejects

soc/software/gps_system/header/gps_system.h

@@ -17,6 +17,7 @@ typedef struct {
 	imu_sample_t imu_sample;
 	navigation_fusion_output_t fused_solution;
 	uint64_t gps_measurement_ticks;
+	uint64_t last_fused_location_tick;
 	uint64_t last_status_tick;
 	bool gps_epoch_ready;
 	bool fusion_enabled;