AP_HAL: remove HAL_COMPASS_DEFAULT define

this doesn't actually allow you to specify a default, despite the name
and a couple of hwdefs trying to use it that way.

This would have stopped being useful when we did the
compass-prority-table stuff - or before.

libraries/AP_HAL/AP_HAL_Boards.h

@@ -84,10 +84,6 @@
 #define HAL_BARO_20789_I2C_SPI  15
 #define HAL_BARO_LPS25H_IMU_I2C 17
 
-/* Compass driver types */
-#define HAL_COMPASS_NONE                0
-#define HAL_COMPASS_HIL_UNUSED          3  // unused
-
 /* Heat Types */
 #define HAL_LINUX_HEAT_PWM 1
 
@@ -200,10 +196,6 @@
 #define HAL_OS_FATFS_IO 0
 #endif
 
-#ifndef HAL_COMPASS_DEFAULT
-#define HAL_COMPASS_DEFAULT HAL_COMPASS_NONE
-#endif
-
 #ifndef HAL_BARO_DEFAULT
 #define HAL_BARO_DEFAULT HAL_BARO_NONE
 #endif

libraries/AP_HAL/board/empty.h

@@ -9,7 +9,6 @@
 #define HAL_STORAGE_SIZE_AVAILABLE  HAL_STORAGE_SIZE
 #define HAL_INS_DEFAULT HAL_INS_NONE
 #define HAL_BARO_DEFAULT HAL_BARO_NONE
-#define HAL_COMPASS_DEFAULT HAL_COMPASS_NONE
 #define CONFIG_HAL_BOARD_SUBTYPE HAL_BOARD_SUBTYPE_NONE
 
 #define HAL_HAVE_BOARD_VOLTAGE 1

libraries/AP_HAL/board/linux.h

@@ -29,7 +29,6 @@
     #define HAL_BOARD_STORAGE_DIRECTORY "."
     #define HAL_INS_DEFAULT HAL_INS_NONE
     #define HAL_BARO_DEFAULT HAL_BARO_NONE
-    #define HAL_COMPASS_DEFAULT HAL_COMPASS_NONE
 #elif CONFIG_HAL_BOARD_SUBTYPE == HAL_BOARD_SUBTYPE_LINUX_PXF || CONFIG_HAL_BOARD_SUBTYPE == HAL_BOARD_SUBTYPE_LINUX_ERLEBOARD
     #if CONFIG_HAL_BOARD_SUBTYPE == HAL_BOARD_SUBTYPE_LINUX_PXF
       #define HAL_INS_PROBE_LIST PROBE_IMU_SPI(Invensense, "mpu9250", ROTATION_ROLL_180_YAW_270)
@@ -85,7 +84,6 @@
     // linux SBC with VectorNav AHRS
     #define HAL_EXTERNAL_AHRS_DEFAULT 1
     #define HAL_SERIAL3_PROTOCOL 36
-    #define HAL_COMPASS_DEFAULT HAL_COMPASS_NONE
     #define HAL_AIRSPEED_TYPE_DEFAULT 0
     #define HAL_GPS_TYPE_DEFAULT 21
     #define HAL_AHRS_EKF_TYPE_DEFAULT 11
@@ -159,10 +157,8 @@
     // Stub the sensors out for now, at least we can build and run
     #define HAL_INS_DEFAULT HAL_INS_NONE
     #define HAL_BARO_DEFAULT HAL_BARO_NONE
-    #define HAL_COMPASS_DEFAULT HAL_COMPASS_NONE
     // only external compasses
     #define HAL_PROBE_EXTERNAL_I2C_COMPASSES
-    #define HAL_COMPASS_DEFAULT HAL_COMPASS_NONE
 #elif CONFIG_HAL_BOARD_SUBTYPE == HAL_BOARD_SUBTYPE_LINUX_OCPOC_ZYNQ
     #define HAL_INS_PROBE_LIST PROBE_IMU_SPI(Invensense, "mpu9250", ROTATION_NONE)
     #define HAL_BARO_PROBE_LIST PROBE_BARO_SPI(MS56XX, "ms5611")
@@ -277,7 +273,6 @@
     #define HAL_BARO_PROBE_LIST PROBE_BARO_SPI(MS56XX, "ms5611")
     // only external compasses
     #define HAL_PROBE_EXTERNAL_I2C_COMPASSES
-    #define HAL_COMPASS_DEFAULT HAL_COMPASS_NONE
     #define HAL_NUM_CAN_IFACES 1
     #define HAL_IMU_TEMP_DEFAULT 55
     #define HAL_HAVE_IMU_HEATER 1
@@ -335,10 +330,6 @@
     #error "no Linux board subtype set"
 #endif
 
-#ifndef HAL_COMPASS_DEFAULT
-    #define HAL_COMPASS_DEFAULT -1
-#endif
-
 #ifndef HAL_OPTFLOW_PX4FLOW_I2C_ADDRESS
     #define HAL_OPTFLOW_PX4FLOW_I2C_ADDRESS 0x42
 #endif

libraries/AP_HAL/board/sitl.h

@@ -42,7 +42,6 @@
 #define HAL_PARAM_DEFAULTS_PATH nullptr
 #define HAL_INS_DEFAULT HAL_INS_NONE
 #define HAL_BARO_DEFAULT HAL_BARO_NONE
-#define HAL_COMPASS_DEFAULT HAL_COMPASS_NONE
 #define HAL_GPIO_A_LED_PIN        61
 #define HAL_GPIO_B_LED_PIN        48
 #define HAL_GPIO_C_LED_PIN        117