e1000: Fixed the following issues with ESB2 (requires ESB2 support):

- Add restriction for ESB2 to MTU size <=9216
- Removed FIFO errors which were not being used
- Fixed issues with loopback
- Power management change for saving state and config space
- WA to disable recieves and reset device on link loss.  Reset needed to be done outside the interrupt context - modified existing tx_timeout_task

Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
Signed-off-by: Jesse Brandeburg <jesse.brandeburg@intel.com>
Signed-off-by: John Ronciak <john.ronciak@intel.com>