idpf: Fix RSS LUT configuration on down interfaces

idpf: Fix RSS LUT configuration on down interfaces

RSS LUT provisioning and queries on a down interface currently return
silently without effect. Users should be able to configure RSS settings
even when the interface is down.

Fix by maintaining RSS configuration changes in the driver's soft copy and
deferring HW programming until the interface comes up.

Fixes: 02cbfba1add5 ("idpf: add ethtool callbacks")
Signed-off-by: Sreedevi Joshi <sreedevi.joshi@intel.com>
Reviewed-by: Aleksandr Loktionov <aleksandr.loktionov@intel.com>
Reviewed-by: Sridhar Samudrala <sridhar.samudrala@intel.com>
Reviewed-by: Emil Tantilov <emil.s.tantilov@intel.com>
Tested-by: Samuel Salin <Samuel.salin@intel.com>
Signed-off-by: Tony Nguyen <anthony.l.nguyen@intel.com>