e1000e: disable ASPM L1 on 82573

On the e1000-devel mailing list, Nils Faerber reported latency issues with
the 82573 LOM on a ThinkPad X60.  It was found to be caused by ASPM L1;
disabling it resolves the latency.  The issue is present in kernels back
to 2.6.34 and possibly 2.6.33.
Reported-by: Nils Faerber <nils.faerber@kernelconcepts.de>
Signed-off-by: Bruce Allan <bruce.w.allan@intel.com>
Cc: stable@kernel.org
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/e1000e/82571.c

@@ -1833,6 +1833,7 @@ struct e1000_info e1000_82573_info = {
 				  | FLAG_HAS_SMART_POWER_DOWN
 				  | FLAG_HAS_AMT
 				  | FLAG_HAS_SWSM_ON_LOAD,
+	.flags2			= FLAG2_DISABLE_ASPM_L1,
 	.pba			= 20,
 	.max_hw_frame_size	= ETH_FRAME_LEN + ETH_FCS_LEN,
 	.get_variants		= e1000_get_variants_82571,