iwlwifi: grap nic access before accessing periphery registers

We need to grap nic access before accessing periphery registers.

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-5000.c b/drivers/net/wireless/iwlwifi/iwl-5000.c
index c5b104f..f3d139b 100644
--- a/drivers/net/wireless/iwlwifi/iwl-5000.c
+++ b/drivers/net/wireless/iwlwifi/iwl-5000.c
@@ -241,9 +241,11 @@
 	 * (PCIe power is lost before PERST# is asserted),
 	 * causing ME FW to lose ownership and not being able to obtain it back.
 	 */
-	 iwl_set_bits_mask_prph(priv, APMG_PS_CTRL_REG,
+	iwl_grab_nic_access(priv);
+	iwl_set_bits_mask_prph(priv, APMG_PS_CTRL_REG,
 				APMG_PS_CTRL_EARLY_PWR_OFF_RESET_DIS,
 				~APMG_PS_CTRL_EARLY_PWR_OFF_RESET_DIS);
+	iwl_release_nic_access(priv);
 
 	spin_unlock_irqrestore(&priv->lock, flags);
 }