AP_Compass: enable in-tree drivers for PHMINI

libraries/AP_Compass/AP_Compass.cpp

@@ -495,7 +495,8 @@ void Compass::_detect_backends(void)
     if (AP_BoardConfig::get_board_type() == AP_BoardConfig::PX4_BOARD_TEST_V1 ||
         AP_BoardConfig::get_board_type() == AP_BoardConfig::PX4_BOARD_TEST_V2 ||
         AP_BoardConfig::get_board_type() == AP_BoardConfig::PX4_BOARD_TEST_V3 ||
-        AP_BoardConfig::get_board_type() == AP_BoardConfig::PX4_BOARD_TEST_V4) {
+        AP_BoardConfig::get_board_type() == AP_BoardConfig::PX4_BOARD_TEST_V4 ||
+        AP_BoardConfig::get_board_type() == AP_BoardConfig::PX4_BOARD_PHMINI) {
         // external i2c bus
         _add_backend(AP_Compass_HMC5843::probe(*this, hal.i2c_mgr->get_device(1, HAL_COMPASS_HMC5843_I2C_ADDR),
                                                true, ROTATION_ROLL_180),
@@ -524,6 +525,10 @@ void Compass::_detect_backends(void)
         _add_backend(AP_Compass_AK8963::probe_mpu9250(*this, 0, ROTATION_ROLL_180_YAW_90),
                      AP_Compass_AK8963::name, false);
     }
+    if (AP_BoardConfig::get_board_type() == AP_BoardConfig::PX4_BOARD_PHMINI) {
+        _add_backend(AP_Compass_AK8963::probe_mpu9250(*this, 0, ROTATION_ROLL_180),
+                     AP_Compass_AK8963::name, false);
+    }
     // also add any px4 level drivers (for canbus magnetometers)
     _add_backend(AP_Compass_PX4::detect(*this), nullptr, false);
 #elif HAL_COMPASS_DEFAULT == HAL_COMPASS_QURT