actuator outputs: always add reverse range param

and remove the possibility to set min > max to reverse.

Initially the idea was to add the checkbox on the UI side, to avoid adding
another param, but I don't think I'll go through the extra effort on the
QGC side.

src/drivers/linux_pwm_out/module.yaml

@@ -1,6 +1,5 @@
 module_name: PWM Output
 actuator_output:
-  add_reverse_range_param: true
   output_groups:
     - param_prefix: PWM_MAIN
       channel_label: 'Channel'