iwlwifi: disable aspm by default

Some iwlwifi devices inexplicably disconnect themselves from the PCI-E
bus causing the predictable failures.  This seems to disappear if ASPM
is disabled.

Signed-off-by: John W. Linville <linville@tuxdriver.com>
diff --git a/drivers/net/wireless/iwlwifi/iwl-agn.c b/drivers/net/wireless/iwlwifi/iwl-agn.c
index 35337b1e..49a7a98 100644
--- a/drivers/net/wireless/iwlwifi/iwl-agn.c
+++ b/drivers/net/wireless/iwlwifi/iwl-agn.c
@@ -33,6 +33,7 @@
 #include <linux/module.h>
 #include <linux/init.h>
 #include <linux/pci.h>
+#include <linux/pci-aspm.h>
 #include <linux/slab.h>
 #include <linux/dma-mapping.h>
 #include <linux/delay.h>
@@ -3968,6 +3969,9 @@
 	/**************************
 	 * 2. Initializing PCI bus
 	 **************************/
+	pci_disable_link_state(pdev, PCIE_LINK_STATE_L0S | PCIE_LINK_STATE_L1 |
+				PCIE_LINK_STATE_CLKPM);
+
 	if (pci_enable_device(pdev)) {
 		err = -ENODEV;
 		goto out_ieee80211_free_hw;