ieee80211: define HT operation CCFS2 field

The Channel Center Frequency Segment 2 field is used in
802.11-2016 for encoding the actual channel position of
the 80+80/160 MHz channel, if the max NSS is restricted.
This is used for backwards compatibility.
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

include/linux/ieee80211.h

@@ -1411,6 +1411,8 @@ struct ieee80211_ht_operation {
 #define		IEEE80211_HT_OP_MODE_PROTECTION_NONHT_MIXED	3
 #define IEEE80211_HT_OP_MODE_NON_GF_STA_PRSNT		0x0004
 #define IEEE80211_HT_OP_MODE_NON_HT_STA_PRSNT		0x0010
+#define IEEE80211_HT_OP_MODE_CCFS2_SHIFT		5
+#define IEEE80211_HT_OP_MODE_CCFS2_MASK			0x1fe0
 
 /* for stbc_param */
 #define IEEE80211_HT_STBC_PARAM_DUAL_BEACON		0x0040