Before adding another AP enumeration mode, clarify the documentation on the current logic. No functional changes. Cc: Eric Dong <eric.dong@intel.com> Cc: Ray Ni <ray.ni@intel.com> Ref: https://bugzilla.tianocore.org/show_bug.cgi?id=1515 Signed-off-by: Laszlo Ersek <lersek@redhat.com> Reviewed-by: Ray Ni <ray.ni@intel.com>