iwlwifi: enable power save setting upon config

This patch enables power save setting from config (iwconfig power)
The sysfs power_level interface is still preserved as it has
mac80211 power implementation is not yet rich enough.

Signed-off-by: Ester Kummer <ester.kummer@intel.com>
Reviewed-by: Tomas Winkler <tomas.winkler@intel.com>
Signed-off-by: Zhu Yi <yi.zhu@intel.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

drivers/net/wireless/iwlwifi/iwl-agn.c

@@ -2875,6 +2875,13 @@ static int iwl4965_mac_config(struct ieee80211_hw *hw, struct ieee80211_conf *co
 		goto out;
 	}
 
+	if (conf->flags & IEEE80211_CONF_PS)
+		ret = iwl_power_set_user_mode(priv, IWL_POWER_INDEX_3);
+	else
+		ret = iwl_power_set_user_mode(priv, IWL_POWER_MODE_CAM);
+	if (ret)
+		IWL_DEBUG_MAC80211("Error setting power level\n");
+
 	IWL_DEBUG_MAC80211("TX Power old=%d new=%d\n",
 			   priv->tx_power_user_lmt, conf->power_level);