e1000e: fix legacy interrupt handling in i219

This fix handles a hardware issue that prevented i219 from
working in legacy interrupts mode (IntMode=0)

Signed-off-by: Yanir Lubetkin <yanirx.lubetkin@intel.com>
Tested-by: Aaron Brown <aaron.f.brown@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>