e1000e: initial support for i217

i217 is the next-generation LOM that will be available on systems with the
Lynx Point Platform Controller Hub (PCH) chipset from Intel.  This patch
provides the initial support for the device.

Signed-off-by: Bruce Allan <bruce.w.allan@intel.com>
Tested-by: Jeff Pieper <jeffrey.e.pieper@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>