i40evf: rename VF adapter specific RSS function

This patch renames old VF adapter specific RSS function to clarify
its scope.

Change-ID: Ie5253083a44c677ebb7709a8a3a18402ad2dc6a6
Signed-off-by: Helin Zhang <helin.zhang@intel.com>
Tested-by: Andrew Bowers <andrewx.bowers@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>