AP_Compass: use HAL_COMPASS_DEFAULT in example code

libraries/AP_Compass/examples/AP_Compass_test/AP_Compass_test.pde

@@ -10,7 +10,9 @@
 #include <AP_HAL_AVR.h>
 #include <AP_HAL_PX4.h>
 #include <AP_HAL_Linux.h>
+#include <AP_HAL_FLYMAPLE.h>
 #include <AP_HAL_Empty.h>
+#include <AP_HAL_VRBRAIN.h>
 
 #include <AP_Math.h>    // ArduPilot Mega Vector/Matrix math Library
 #include <AP_Declination.h>
@@ -18,11 +20,20 @@
 
 const AP_HAL::HAL& hal = AP_HAL_BOARD_DRIVER;
 
-#if CONFIG_HAL_BOARD == HAL_BOARD_PX4
-AP_Compass_PX4 compass;
+#define CONFIG_COMPASS HAL_COMPASS_DEFAULT
+
+#if CONFIG_COMPASS == HAL_COMPASS_PX4
+static AP_Compass_PX4 compass;
+#elif CONFIG_COMPASS == HAL_COMPASS_VRBRAIN
+static AP_Compass_VRBRAIN compass;
+#elif CONFIG_COMPASS == HAL_COMPASS_HMC5843
+static AP_Compass_HMC5843 compass;
+#elif CONFIG_COMPASS == HAL_COMPASS_HIL
+static AP_Compass_HIL compass;
 #else
-AP_Compass_HMC5843 compass;
+ #error Unrecognized CONFIG_COMPASS setting
 #endif
+
 uint32_t timer;
 
 void setup() {