iwlwifi: always support idle mode for agn devices

For agn devices, always support idle mode which help power
consumption in idle unassociated state.

Signed-off-by: Wey-Yi Guy <wey-yi.w.guy@intel.com>
diff --git a/drivers/net/wireless/iwlwifi/iwl-power.c b/drivers/net/wireless/iwlwifi/iwl-power.c
index 25f7d47..1d1bf32 100644
--- a/drivers/net/wireless/iwlwifi/iwl-power.c
+++ b/drivers/net/wireless/iwlwifi/iwl-power.c
@@ -356,8 +356,7 @@
 
 	if (priv->cfg->base_params->broken_powersave)
 		iwl_power_sleep_cam_cmd(priv, cmd);
-	else if (priv->cfg->base_params->supports_idle &&
-		 priv->hw->conf.flags & IEEE80211_CONF_IDLE)
+	else if (priv->hw->conf.flags & IEEE80211_CONF_IDLE)
 		iwl_static_sleep_cmd(priv, cmd, IWL_POWER_INDEX_5, 20);
 	else if (priv->cfg->ops->lib->tt_ops.lower_power_detection &&
 		 priv->cfg->ops->lib->tt_ops.tt_power_mode &&