e1000e: do not disable receiver on 82574/82583

Due to a hardware erratum, the receiver on 82574 and 82583 should not be
stopped once it has been started.

Signed-off-by: Bruce Allan <bruce.w.allan@intel.com>
Tested-by: Aaron Brown <aaron.f.brown@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>