ixgbe: add support for displaying ntuple filters via the nfc interface

This code adds support for displaying the filters that were added via the
nfc interface.  This is primarily to test the interface for now, but I am
also looking into the feasibility of moving all of the ntuple filter code
in ixgbe over to the nfc interface since it seems to be better implemented.

Signed-off-by: Alexander Duyck <alexander.h.duyck@intel.com>
Tested-by: Ross Brattain <ross.b.brattain@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>