i40e: Strip out debugfs hook for Flow Director filter programming

This  interface was only ever meant for debug only. Since it is not
supposed to be here we are removing it.

Change-ID: Id771a1e5e7d3e2b4b7f56591b61fb48c921e1d04
Signed-off-by: Alexander Duyck <alexander.h.duyck@intel.com>
Tested-by: Andrew Bowers <andrewx.bowers@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>