iwlwifi: add possibility to disable tx_power calibration

This patch adds the possibility to disable the tx_power calibration.
In 5000 HW, this calibration is implemented in uCode, hence, it is
disabled in driver by default.

Signed-off-by: Emmanuel Grumbach <emmanuel.grumbach@intel.com>
Signed-off-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>
diff --git a/drivers/net/wireless/iwlwifi/iwl-4965.c b/drivers/net/wireless/iwlwifi/iwl-4965.c
index be6b6eb..6d249bb 100644
--- a/drivers/net/wireless/iwlwifi/iwl-4965.c
+++ b/drivers/net/wireless/iwlwifi/iwl-4965.c
@@ -2103,8 +2103,9 @@
 	priv->temperature = temp;
 	set_bit(STATUS_TEMPERATURE, &priv->status);
 
-	if (unlikely(!test_bit(STATUS_SCANNING, &priv->status)) &&
-		     iwl4965_is_temp_calib_needed(priv))
+	if (!priv->disable_tx_power_cal &&
+	     unlikely(!test_bit(STATUS_SCANNING, &priv->status)) &&
+	     iwl4965_is_temp_calib_needed(priv))
 		queue_work(priv->workqueue, &priv->txpower_work);
 }