i40e: support for suspend and resume

Add basic support for handling suspend and resume.  We'll add
Wake-on-LAN support later.

Change-Id: Iea5e11c81bd9289a5bdbf086de8f626911a0b5ce
Signed-off-by: Shannon Nelson <shannon.nelson@intel.com>
Signed-off-by: Jesse Brandeburg <jesse.brandeburg@intel.com>
Tested-by: Kavindya Deegala <kavindya.s.deegala@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>