e1000e: fix I217/I218 PHY initialization flow

The initialization of the PHY on I217/I218, while similar to 82579, must
also check to see if the MAC and PHY are in the same mode (PCIe vs. SMBus)
otherwise the PHY will be inaccessible by the MAC.

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>