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>