AP_Param: fixed saving of sensor calibration

this fixes the saving of the accel and gyro calibration to EEPROM,
which was initially broken by the AP_Param conversion

ArduCopter/Parameters.h

@@ -92,7 +92,7 @@ public:
 	//
 	// 140: Sensor parameters
 	//
-	k_param_IMU_calibration = 140,
+	k_param_imu = 140, // sensor calibration
     k_param_battery_monitoring,
     k_param_volt_div_ratio,
     k_param_curr_amp_per_volt,

ArduCopter/Parameters.pde

@@ -142,7 +142,8 @@ static const AP_Param::Info var_info[] PROGMEM = {
 	// variables not in the g class which contain EEPROM saved variables
 	GOBJECT(compass,        "COMPASS_", Compass),
 	GOBJECT(gcs0,			"SR0_",     GCS_MAVLINK),
-	GOBJECT(gcs3,			"SR3_",     GCS_MAVLINK)
+	GOBJECT(gcs3,			"SR3_",     GCS_MAVLINK),
+	GOBJECT(imu,			"IMU_",     IMU)
 };
 
 

ArduPlane/Parameters.h

@@ -68,7 +68,7 @@ public:
         //
         // 130: Sensor parameters
         //
-        k_param_IMU_calibration = 130,
+        k_param_imu = 130,  // sensor calibration
         k_param_altitude_mix,
         k_param_airspeed_ratio,
         k_param_ground_temperature,

ArduPlane/Parameters.pde

@@ -123,7 +123,8 @@ static const AP_Param::Info var_info[] PROGMEM = {
 	// variables not in the g class which contain EEPROM saved variables
 	GOBJECT(compass,                "COMPASS_",	Compass),
 	GOBJECT(gcs0,					"SR0_",     GCS_MAVLINK),
-	GOBJECT(gcs3,					"SR3_",     GCS_MAVLINK)
+	GOBJECT(gcs3,					"SR3_",     GCS_MAVLINK),
+	GOBJECT(imu,					"IMU_",     IMU)
 };