iavf: rename I40E_ADMINQ_DESC

Take care of some renames containing I40E_ADMINQ_DESC.

Signed-off-by: Jesse Brandeburg <jesse.brandeburg@intel.com>
Tested-by: Andrew Bowers <andrewx.bowers@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>