amd64, i386: remove profile directive from NOTES
Support for this directive has been removed in config(8) on main, which leaves us unable to build LINT with newer config(8). It's believed that mcount-based profiling didn't really work on modern systems anyways, so the value of testing this is low. We avoid providing limited backwards compatibility here to continue and warn folks that may somehow be deploying real-world configs with `profile` specified. This is a direct commit to stable/12, but a partial MFC of aa3ea612.