iwlwifi help in kernel configuration makes reference to Documentation/networking/README.iwlwifi but such file does not exist.
People have been complaining about this for awhile. I have no idea why this is not committed in the mainline tree. Here's a link to the file. http://www.intellinuxwireless.org/repos/?p=iwlwifi.git;a=blob_plain;f=README.iwlwifi;hb=HEAD
I'm going to close this bug. I did email the maintainer at Intel and kindly asked him to commit the documentation file. That's about the best I can do. If it ever makes the mainline one of us can reopen this bug and I will backport it if we think its absolutely necessary. Here's the upstream bug about the same issue: http://bugzilla.kernel.org/show_bug.cgi?id=9765
fyi: a patch has been queued upstream to remove the references to README.iwlwifi http://marc.info/?l=linux-wireless&m=120036405729704&w=2
this is fixed in 2.6.25