e1000: always call e1000_check_for_link() on e1000_ce4100 MACs.

Interrupts about link lost or rx sequence errors are not reported by
the ce4100 hardware, leading to transitions from link UP to link DOWN
never being reported.

Signed-off-by: Nicolas Schichan <nschichan@freebox.fr>
Tested-by: Aaron Brown <aaron.f.brown@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>