i40e: Further implementation of LLDP

This code implements driver code changes necessary for LLDP
Agent support. Modified i40e_aq_start_lldp() and
i40e_aq_stop_lldp() adding false parameter whether LLDP state
should be persistent across power cycles.

Signed-off-by: Aleksandr Loktionov <aleksandr.loktionov@intel.com>
Tested-by: Andrew Bowers <andrewx.bowers@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>