e1000e: Disable ASPM L1 on 82574

ASPM on the 82574 causes trouble. Currently the driver disables L0s for
this NIC but only disables L1 if the MTU is >1500. This patch simply
causes L1 to be disabled regardless of the MTU setting.
Signed-off-by: Chris Boot <bootc@bootc.net>
Cc: "Wyborny, Carolyn" <carolyn.wyborny@intel.com>
Cc: Nix <nix@esperi.org.uk>
Link: https://lkml.org/lkml/2012/3/19/362Tested-by: Jeff Pieper <jeffrey.e.pieper@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>

drivers/net/ethernet/intel/e1000e/82571.c

@@ -2074,6 +2074,7 @@ const struct e1000_info e1000_82574_info = {
 				  | FLAG_HAS_CTRLEXT_ON_LOAD,
 	.flags2			 = FLAG2_CHECK_PHY_HANG
 				  | FLAG2_DISABLE_ASPM_L0S
+				  | FLAG2_DISABLE_ASPM_L1
 				  | FLAG2_NO_DISABLE_RX
 				  | FLAG2_DMA_BURST,
 	.pba			= 32,