iavf: convert to NAPI IRQ affinity API

Commit bd7c0060 ("net: move aRFS rmap management and CPU affinity
to core") allows the drivers to delegate the IRQ affinity to the NAPI
instance. However, the driver needs to use a persistent NAPI config
and explicitly set/unset the NAPI<->IRQ association.

Convert to the new IRQ affinity API.

Reviewed-by: Jacob Keller <jacob.e.keller@intel.com>
Signed-off-by: Ahmed Zaki <ahmed.zaki@intel.com>
Tested-by: Rafal Romanowski <rafal.romanowski@intel.com>
Signed-off-by: Tony Nguyen <anthony.l.nguyen@intel.com>