boards: px4/fmu-v5 disable px4io in rc.board_defaults

- avoid keeping this kind of logic in the common rcS

ROMFS/px4fmu_common/init.d/rcS

@@ -271,19 +271,21 @@ else
 		param set SYS_AUTOCONFIG 0
 	fi
 
+	#
+	# Set USE_IO flag.
+	#
+	if param compare -s SYS_USE_IO 1
+	then
+		set USE_IO yes
+	fi
+
 	#
 	# Check if PX4IO present and update firmware if needed.
 	# Assumption IOFW set to firmware file and IO_PRESENT = no
 	#
 
-	if [ -f $IOFW ]
+	if [ -f $IOFW -a $USE_IO = yes ]
 	then
-		# Check for the mini using build with px4io fw file
-		# but not a px4IO
-		if ver hwtypecmp V540 V560
-		then
-			param set SYS_USE_IO 0
-		else
 		if px4io checkcrc ${IOFW}
 		then
 			set IO_PRESENT yes
@@ -319,22 +321,13 @@ else
 				tune_control play -t 18 # tune 18 = PROG_PX4IO_ERR
 			fi
 		fi
-		fi
-	fi
-
-	#
-	# Set USE_IO flag.
-	#
-	if param compare -s SYS_USE_IO 1
-	then
-		set USE_IO yes
-	fi
 
 		if [ $USE_IO = yes -a $IO_PRESENT = no ]
 		then
 			echo "PX4IO not found"
 			tune_control play error
 		fi
+	fi
 
 	#
 	# RC update (map raw RC input to calibrate manual control)

boards/px4/fmu-v5/init/rc.board_defaults

@@ -9,6 +9,12 @@ then
 
 fi
 
+# disable px4io on HolyBro mini (V540) and CUAV V5nano (V560)
+if ver hwtypecmp V540 V560
+then
+	param set SYS_USE_IO 0
+fi
+
 set LOGGER_BUF 64
 
 rgbled_pwm start