cfg80211: add kerneldoc entry for "vht_cap"

Signed-off-by: Robert P. J. Day <rpjday@crashcourse.ca>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

include/net/cfg80211.h

@@ -243,6 +243,7 @@ struct ieee80211_sta_vht_cap {
  *	rates" IE, i.e. CCK rates first, then OFDM.
  * @n_bitrates: Number of bitrates in @bitrates
  * @ht_cap: HT capabilities in this band
+ * @vht_cap: VHT capabilities in this band
  */
 struct ieee80211_supported_band {
 	struct ieee80211_channel *channels;