e1000e: remove unnecessary 82577 workaround causing link issues

A workaround for pre-release versions of 82577 is causing link issues on
some switches.  The workaround is no longer needed on production parts so
remove it.

Signed-off-by: Bruce Allan <bruce.w.allan@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>