virtio: hookup irq_get_affinity callback

virtio: hookup irq_get_affinity callback

struct bus_type has a new callback for retrieving the IRQ affinity for a
device. Hook this callback up for virtio based devices.

Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Ming Lei <ming.lei@redhat.com>
Reviewed-by: John Garry <john.g.garry@oracle.com>
Signed-off-by: Daniel Wagner <wagi@kernel.org>
Link: https://lore.kernel.org/r/20241202-refactor-blk-affinity-helpers-v6-3-27211e9c2cd5@kernel.org
Signed-off-by: Jens Axboe <axboe@kernel.dk>