iwlwifi: nvm: honour VHT enable flag

Some devices don't support VHT (802.11ac) and this is encoded
in the data stored in the NVM. Read the flag and use it to set
up the VHT capabilities accordingly.
Reviewed-by: NEmmanuel Grumbach <emmanuel.grumbach@intel.com>
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>

drivers/net/wireless/iwlwifi/iwl-nvm-parse.c

@@ -89,6 +89,7 @@ enum nvm_sku_bits {
 	NVM_SKU_CAP_BAND_24GHZ	= BIT(0),
 	NVM_SKU_CAP_BAND_52GHZ	= BIT(1),
 	NVM_SKU_CAP_11N_ENABLE	= BIT(2),
+	NVM_SKU_CAP_11AC_ENABLE	= BIT(3),
 };
 
 /* radio config bits (actual values from NVM definition) */
@@ -258,8 +259,6 @@ static void iwl_init_vht_hw_capab(const struct iwl_cfg *cfg,
 				  struct iwl_nvm_data *data,
 				  struct ieee80211_sta_vht_cap *vht_cap)
 {
-	/* For now, assume new devices with NVM are VHT capable */
-
 	vht_cap->vht_supported = true;
 
 	vht_cap->cap = IEEE80211_VHT_CAP_SHORT_GI_80 |
@@ -292,7 +291,8 @@ static void iwl_init_vht_hw_capab(const struct iwl_cfg *cfg,
 }
 
 static void iwl_init_sbands(struct device *dev, const struct iwl_cfg *cfg,
-			    struct iwl_nvm_data *data, const __le16 *nvm_sw)
+			    struct iwl_nvm_data *data, const __le16 *nvm_sw,
+			    bool enable_vht)
 {
 	int n_channels = iwl_init_channel_map(dev, cfg, data,
 			&nvm_sw[NVM_CHANNELS]);
@@ -314,7 +314,8 @@ static void iwl_init_sbands(struct device *dev, const struct iwl_cfg *cfg,
 	n_used += iwl_init_sband_channels(data, sband, n_channels,
 					  IEEE80211_BAND_5GHZ);
 	iwl_init_ht_hw_capab(cfg, data, &sband->ht_cap, IEEE80211_BAND_5GHZ);
-	iwl_init_vht_hw_capab(cfg, data, &sband->vht_cap);
+	if (enable_vht)
+		iwl_init_vht_hw_capab(cfg, data, &sband->vht_cap);
 
 	if (n_channels != n_used)
 		IWL_ERR_DEV(dev, "NVM: used only %d of %d channels\n",
@@ -380,7 +381,8 @@ iwl_parse_nvm_data(struct device *dev, const struct iwl_cfg *cfg,
 	data->hw_addr[4] = hw_addr[5];
 	data->hw_addr[5] = hw_addr[4];
 
-	iwl_init_sbands(dev, cfg, data, nvm_sw);
+	iwl_init_sbands(dev, cfg, data, nvm_sw,
+			sku & NVM_SKU_CAP_11AC_ENABLE);
 
 	data->calib_version = 255;   /* TODO:
 					this value will prevent some checks from