e1000e: disable EEE support by default

Based on community feedback, EEE should be disabled by default until the
IEEE802.3az specification has been finalized.

Cc: bhutchings@solarflare.com
Signed-off-by: Bruce Allan <bruce.w.allan@intel.com>
Tested-by: Emil Tantilov <emil.s.tantilov@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>