refactor l3gd20: use driver base class

boards/px4/fmu-v3/init/rc.board_sensors

@@ -78,8 +78,8 @@ then
 		ak09916 -X -R 6 start
 	fi
 
-	# external L3GD20H is rotated 180 degrees yaw
-	l3gd20 -X -R 4 start
+	# (external) L3GD20H is rotated 180 degrees yaw
+	l3gd20 -s -R 4 start
 
 	# (external) LSM303D is rotated 270 degrees yaw
 	lsm303d -s -R 6 start
@@ -113,7 +113,7 @@ else
 	# else: On the PixhawkMini the mpu9250 has been disabled due to HW errata
 	fi
 
-	l3gd20 start
+	l3gd20 -s start
 	lsm303d -s start
 fi