Rover: support raw IMU logging

APMrover2/APMrover2.pde

@@ -737,6 +737,8 @@ static void one_second_loop(void)
         }
         counter = 0;
     }
+
+    ins.set_raw_logging(should_log(MASK_LOG_IMU_RAW));
 }
 
 static void update_GPS_50Hz(void)

APMrover2/defines.h

@@ -89,6 +89,7 @@ enum mode {
 #define MASK_LOG_STEERING  		(1<<13)
 #define MASK_LOG_RC     		(1<<14)
 #define MASK_LOG_WHEN_DISARMED  (1UL<<16)
+#define MASK_LOG_IMU_RAW        (1UL<<19)
 
 // Waypoint Modes
 // ----------------

APMrover2/system.pde

@@ -248,6 +248,9 @@ static void startup_ground(void)
     // so set serial ports non-blocking once we are ready to drive
     serial_manager.set_blocking_writes_all(false);
 
+    ins.set_raw_logging(should_log(MASK_LOG_IMU_RAW));
+    ins.set_dataflash(&DataFlash);
+
 	gcs_send_text_P(SEVERITY_LOW,PSTR("\n\n Ready to drive."));
 }