igb: Fix link setup for I210 devices

This patch changes the setup copper link function to use a switch
statement for the PHY id's available for the given PHY types.  It
also adds a case for the I210 PHY id, so the appropriate setup link
function is called for it.

Signed-off-by: Carolyn Wyborny <carolyn.wyborny@intel.com>
Tested-by: Aaron Brown <aaron.f.brown@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>