Adapt startup scripts to new pwm systemcmd interface

ROMFS/px4fmu_common/init.d/rc.custom_dji_f330_mkblctrl

@@ -83,10 +83,6 @@ then
 	usleep 5000
 
 	sh /etc/init.d/rc.io
-	# Set PWM values for DJI ESCs
-	px4io idle 900 900 900 900
-	px4io min 1200 1200 1200 1200
-	px4io max 1800 1800 1800 1800
 else
 	fmu mode_pwm
 	# Start MAVLink (on UART1 / ttyS0)
@@ -107,9 +103,11 @@ else
 fi
 
 #
-# Set PWM output frequency
+# Set disarmed, min and max PWM signals
 #
-#pwm -u 400 -m 0xff
+pwm disarmed -c 1234 -p 900
+pwm min -c 1234 -p 1200
+pwm max -c 1234 -p 1800
 
 #
 # Start common for all multirotors apps