Basically just start with what you're aiming to enable and work backwards (as you've started to do). With judicious use of grep find out where that symbol is defined. If it's in arch configs for other arches but not your own, it's probably that.
There may be better tools out there to do this, but in my experience just sleuthing it out a bit will answer your question. The Kconfig system can be complex, but the files are pretty readable.
Bah, Imperial Units all the way. How else would I know how many stone I weigh, or how many King's Pubes I am tall? I don't want to convert from kilometers (whatever those are!) to gentlemans-strides or shilling miles to get where I'm going.