i40e: Fix GPL header

The GPL header included in each file in the i40e driver doesn't
need to include the "this program" text since this driver
is already part of the larger kernel.

Signed-off-by: Greg Rose <gregory.v.rose@intel.com>
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>