i40e: Specify AQ event opcode to wait for

To add a little flexibility to the nvmupdate facility, this code adds the
ability to specify an AQ event opcode to wait on after the Exec_AQ request.

Change-ID: Iddbfd63c3de8df3edb9d3e90678b08989bc4946e
Signed-off-by: Shannon Nelson <shannon.nelson@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>