i40e: Do not expose fd-sb commands from debugfs

Ethtool -k/-K can handle this so we do not need it in debugfs.

Change-ID: I9df692f10a60b71805f8f48d3b87c7da3820b2aa
Signed-off-by: Anjali Singhai Jain <anjali.singhai@intel.com>
Signed-off-by: Catherine Sullivan <catherine.sullivan@intel.com>
Tested-by: Kavindya Deegala <kavindya.s.deegala@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>