i40e: disable packet split

The driver and hardware support splitting packets on headers
but with the use of GRO we don't need the extra bus
overhead, so make this driver more like igb and ixgbe and
disable packet split.

Change-ID: Id42f2c3736baa9d5bdfe1f72d64226e7d8ebd737
Signed-off-by: Jesse Brandeburg <jesse.brandeburg@intel.com>
Tested-by: Kavindya Deegala <kavindya.s.deegala@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>