iavf: remove some unused functions and pointless wrappers

Remove iavf_aq_get_rss_lut(), iavf_aq_get_rss_key(), iavf_vf_reset().

Remove some "OS specific memory free for shared code" wrappers ;)

Signed-off-by: Przemek Kitszel <przemyslaw.kitszel@intel.com>
Signed-off-by: Tony Nguyen <anthony.l.nguyen@intel.com>