Well, why do you need to change that?
There is probably a bug in the kernel card recognition, the 440 and the 420 are probably very close. You may want to report this bug, however, as this is only used in an information purpose, it won't change much if they fix it.
Keep in mind : you are using nvidia drivers, you aren't even using kernel drivers that may be confused about this bug.
NB : what kernel are you running anyways? If this really bother you, it might have been fixed in latest kernel version, if you want to try.