ixgbe: convert to ndo_fix_features

Private rx_csum flags are now duplicate of netdev->features &
NETIF_F_RXCSUM.  We remove those duplicates and now use the net_device_ops
ndo_set_features.  This was based on the original patch submitted by
Michal Miroslaw <mirq-linux@rere.qmqm.pl>.  I also removed the special
case not requiring a reset for X540 hardware.  It is needed just as it is
in 82599 hardware.

Signed-off-by: Don Skidmore <donald.c.skidmore@intel.com>
Cc:  Michal Miroslaw <mirq-linux@rere.qmqm.pl>
Tested-by: Phil Schmitt <phillip.j.schmitt@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>