pixhawk1 and mnt parameters

hello my friend
I have pixhawk 1 cuav model, i have upgraded my pixhawk to lastest firmware ( arducopter v4.1.1 hexa) .
I have problem to set mnt_type. in new firmware is not possible to set the mnt_type and other mnt paremeter

If it’s a 1Mb Pixhawk1 board the Mnt features have been limited out. You could use the Custom Firmware Builder to enable them as long as the total options don’t exceed the 1Mb limit. Also, this will be the 4.2.0-Developement version of firmware.
Custom Firmware Builder