FW: Handle PWM params in startup

ROMFS/px4fmu_common/init.d/rc.fw_defaults

@@ -17,12 +17,21 @@ then
 	
 	param set MIS_LTRMIN_ALT 25
 	param set MIS_TAKEOFF_ALT 25
+	param set PWM_AUX_DISARMED 1500
+	param set PWM_AUX_MIN 1000
+	param set PWM_AUX_MAX 2000
 fi
 
+# tell the mixer to use parameters for these instead
+set PWM_RATE p:PWM_RATE
+set PWM_DISARMED p:PWM_DISARMED
+set PWM_MIN p:PWM_MIN
+set PWM_MAX p:PWM_MAX
+set PWM_AUX_DISARMED p:PWM_AUX_DISARMED
+set PWM_AUX_MIN p:PWM_AUX_MIN
+set PWM_AUX_MAX p:PWM_AUX_MAX
+
 # This is the gimbal pass mixer
 set MIXER_AUX pass
 set PWM_AUX_RATE 50
 set PWM_AUX_OUT 1234
-set PWM_AUX_DISARMED 1500
-set PWM_AUX_MIN 1000
-set PWM_AUX_MAX 2000