cfg80211: Fix order of enum nl80211_band_iftype_attr documentation

And fix the comment.

Signed-off-by: Ilan Peer <ilan.peer@intel.com>
Signed-off-by: Luca Coelho <luciano.coelho@intel.com>
Link: https://lore.kernel.org/r/iwlwifi.20211129152938.4ef43aff0c5d.I96dcb743bcd4f387ba4cfaa61987aeb642ad762b@changeid


Signed-off-by: Johannes Berg <johannes.berg@intel.com>