AP_HAL: added possibility to use several compassed on Navio 2

libraries/AP_HAL/AP_HAL_Boards.h

@@ -96,6 +96,7 @@
 #define HAL_COMPASS_QFLIGHT   11
 #define HAL_COMPASS_QURT      12
 #define HAL_COMPASS_BBBMINI   13
+#define HAL_COMPASS_NAVIO2    14
 
 // Heat Types
 #define HAL_LINUX_HEAT_PWM 1
@@ -300,7 +301,7 @@
 #define HAL_BARO_MS5611_I2C_BUS 1
 #define HAL_BARO_MS5611_I2C_ADDR 0x77
 #define HAL_BARO_MS5611_USE_TIMER false
-#define HAL_COMPASS_DEFAULT HAL_COMPASS_AK8963_MPU9250
+#define HAL_COMPASS_DEFAULT HAL_COMPASS_NAVIO2
 /* HMC5843 can be an external compass */
 #define HAL_COMPASS_HMC5843_I2C_BUS 1
 #define HAL_COMPASS_HMC5843_I2C_ADDR 0x1E