ncr5380: Remove unused hostdata fields

Remove unused fields from hostdata structs declared with the
NCR5380_implementation_fields macro.

Signed-off-by: Finn Thain <fthain@telegraphics.com.au>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Christoph Hellwig <hch@lst.de>