cfg80211: regulatory: introduce NL80211_RRF_AUTO_BW rule flag

Introduce NL80211_RRF_AUTO_BW rule flag. If this flag set
maximum available bandwidth should be calculated base on
contiguous rules and wider channels will be allowed to cross
multiple contiguous/overlapping frequency ranges.

In case of old kernels maximum bandwidth from regulatory
rule will be used, while there is no NL80211_RRF_AUTO_BW flag.

This fixes the previous commit 9752482083
("cfg80211: regulatory introduce maximum bandwidth calculation")
which was found to be a problem for userspace API compatibility.

Signed-off-by: Janusz Dziedzic <janusz.dziedzic@tieto.com>
[edit commit log, use sizeof()]
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

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

net/wireless/genregdb.awk

@@ -105,6 +105,8 @@ function parse_reg_rule()
 			flags = flags "\n\t\t\tNL80211_RRF_NO_IR | "
 		} else if (flagarray[arg] == "NO-IR") {
 			flags = flags "\n\t\t\tNL80211_RRF_NO_IR | "
+		} else if (flagarray[arg] == "AUTO-BW") {
+			flags = flags "\n\t\t\tNL80211_RRF_AUTO_BW | "
 		}
 
 	}