i40e/i40evf: implement KR2 support

The new devices need a new device ID some other defines to
handle the new 20G speed for KR2.

Change-ID: I03f717e364afe59657e8c9ce5ffaad856b4b21df
Signed-off-by: Jesse Brandeburg <jesse.brandeburg@intel.com>
Signed-off-by: Piotr Raczynski <piotr.raczynski@intel.com>
Tested-by: Jim Young <james.m.young@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>