e1000e: Enable DMA Burst Mode on 82574 by default.

Performance testing has shown that enabling DMA burst on 82574
improves performance on small packets, so enable it by default.
Signed-off-by: NMatthew Vick <matthew.vick@intel.com>
Tested-by: NJeff Pieper <jeffrey.e.pieper@intel.com>
Signed-off-by: NJeff Kirsher <jeffrey.t.kirsher@intel.com>

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

@@ -2062,7 +2062,8 @@ const struct e1000_info e1000_82574_info = {
 				  | FLAG_HAS_CTRLEXT_ON_LOAD,
 	.flags2			  = FLAG2_CHECK_PHY_HANG
 				  | FLAG2_DISABLE_ASPM_L0S
-				  | FLAG2_NO_DISABLE_RX,
+				  | FLAG2_NO_DISABLE_RX
+				  | FLAG2_DMA_BURST,
 	.pba			= 32,
 	.max_hw_frame_size	= DEFAULT_JUMBO,
 	.get_variants		= e1000_get_variants_82571,