e1000e: enable support for new device IDs

The device IDs 0x15a0 and 0x15a1 are new SKUs that contain the same MAC as
I217 and same PHY as I218.

The device IDs 0x15a2 and 0x15a3 are the same as existing I218 SKUs.

Signed-off-by: Bruce Allan <bruce.w.allan@intel.com>
Tested-by: Aaron Brown <aaron.f.brown@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>