igc: Update the MAC reset flow

Use Device Reset flow instead of Port Reset flow.
This flow performs a reset of the entire controller device,
resulting in a state nearly approximating the state
following a power-up reset or internal PCIe reset,
except for system PCI configuration.

Signed-off-by: Sasha Neftin <sasha.neftin@intel.com>
Tested-by: Aaron Brown <aaron.f.brown@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>