ixgbe: fix linking at 100Mbps on copper devices with MNG FW enabled

Driver was calling setup_link to make sure that fiber interfaces with MNG FW
enabled will get link on probe because the laser was most likely turned off.
This prevented non-fiber devices with MNG FW from linking at 100Mbps.

This patch adds a check to only call setup_link for fiber devices.

Reported-and-by: Tony Luck <tony.luck@intel.com>
Signed-off-by: Emil Tantilov <emil.s.tantilov@intel.com>
Tested-by: Tony Luck <tony.luck@intel.com>
Tested-by: Phil Schmitt <phillip.j.schmitt@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>