e1000e: Do not allow CRC stripping to be disabled on 82579 w/ jumbo frames

e1000e: Do not allow CRC stripping to be disabled on 82579 w/ jumbo frames

 The driver wasn't allowing jumbo frames to be
 enabled when CRC stripping was disabled, however it was allowing CRC
 stripping to be disabled while jumbo frames were enabled.  This fixes that by
 making it so that the NETIF_F_RXFCS flag cannot be set when jumbo frames are
 enabled on 82579 and newer parts.

Signed-off-by: Alexander Duyck <alexander.h.duyck@redhat.com>
Tested-by: Aaron Brown <aaron.f.brown@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>