e1000e: convert to netdev features/hw_features API

Private rx_csum flags are now duplicate of netdev->features &
NETIF_F_RXCSUM.  Remove those duplicates and use the net_device_ops
ndo_set_features.  This is based on the original patch submitted by
Michał Mirosław <mirq-linux@rere.qmqm.pl>

Cc: Michał Mirosław <mirq-linux@rere.qmqm.pl>
Signed-off-by: Bruce Allan <bruce.w.allan@intel.com>
Tested-by: Aaron Brown <aaron.f.brown@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>

drivers/net/ethernet/intel/e1000e/80003es2lan.c

@@ -1498,7 +1498,6 @@ struct e1000_info e1000_es2_info = {
 				  | FLAG_HAS_JUMBO_FRAMES
 				  | FLAG_HAS_WOL
 				  | FLAG_APME_IN_CTRL3
-				  | FLAG_RX_CSUM_ENABLED
 				  | FLAG_HAS_CTRLEXT_ON_LOAD
 				  | FLAG_RX_NEEDS_RESTART /* errata */
 				  | FLAG_TARC_SET_BIT_ZERO /* errata */