cfg80211: apply same mandatory rate flags for 5GHz and 6GHz

For the new 6GHz band the same rules apply for mandatory rates so
add it to set_mandatory_flags_band() function.
Reviewed-by: NPieter-Paul Giesberts <pieter-paul.giesberts@broadcom.com>
Reviewed-by: NLeon Zegers <leon.zegers@broadcom.com>
Signed-off-by: NArend van Spriel <arend.vanspriel@broadcom.com>
Link: https://lore.kernel.org/r/1564745465-21234-9-git-send-email-arend.vanspriel@broadcom.comSigned-off-by: NJohannes Berg <johannes.berg@intel.com>

net/wireless/util.c

@@ -156,6 +156,7 @@ static void set_mandatory_flags_band(struct ieee80211_supported_band *sband)
 
 	switch (sband->band) {
 	case NL80211_BAND_5GHZ:
+	case NL80211_BAND_6GHZ:
 		want = 3;
 		for (i = 0; i < sband->n_bitrates; i++) {
 			if (sband->bitrates[i].bitrate == 60 ||