iwlwifi: mvm: Advertise support for AP channel width change

The iwlmvm driver supports channel width change in AP mode.  Add the
proper flag.

Signed-off-by: Ilan Peer <ilan.peer@intel.com>
Signed-off-by: Luca Coelho <luciano.coelho@intel.com>
diff --git a/drivers/net/wireless/intel/iwlwifi/mvm/mac80211.c b/drivers/net/wireless/intel/iwlwifi/mvm/mac80211.c
index 6d60645..5dd77e3 100644
--- a/drivers/net/wireless/intel/iwlwifi/mvm/mac80211.c
+++ b/drivers/net/wireless/intel/iwlwifi/mvm/mac80211.c
@@ -624,6 +624,7 @@
 	hw->wiphy->features |= NL80211_FEATURE_P2P_GO_CTWIN |
 			       NL80211_FEATURE_LOW_PRIORITY_SCAN |
 			       NL80211_FEATURE_P2P_GO_OPPPS |
+			       NL80211_FEATURE_AP_MODE_CHAN_WIDTH_CHANGE |
 			       NL80211_FEATURE_DYNAMIC_SMPS |
 			       NL80211_FEATURE_STATIC_SMPS |
 			       NL80211_FEATURE_SUPPORTS_WMM_ADMISSION;