posix-configs: start HMC5883 before MPU9250 in DF

We need to start the external mag before we start the internal mag on
the MPU9250 because the ekf2 does not support voting for the sensor with
the highest priority (or failures) yet, so it will just subscribe to
whatever is at 0.

posix-configs/eagle/flight/px4.config

@@ -4,9 +4,9 @@ param set SYS_AUTOSTART 4001
 gps start -d /dev/tty-4
 sleep 1
 param set MAV_TYPE 2
+df_hmc5883_wrapper start
 df_mpu9250_wrapper start
 df_bmp280_wrapper start
-df_hmc5883_wrapper start
 df_trone_wrapper start
 #df_isl29501_wrapper start
 sensors start