i40e: enable LSE poke and simplify link state

The driver can do a simpler job of managing link state by simply
using the admin queue receive event for link events as a doorbell
that tells the driver to update link state.

Additionally, add a workaround will help make sure the link state in the
hardware is consistent with the link state the driver is reporting
by refreshing the link state every service task interval.

Change-ID: Ib95b5b7b8cc016e97d8009f6363c9f9eed301444
Signed-off-by: Jesse Brandeburg <jesse.brandeburg@intel.com>
Tested-by: Jim Young <jamesx.m.young@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>