[PATCH] PATCH: libata. Add ->data_xfer method

We need to pass the device in order to do per device checks such as
32bit I/O enables. With the changes to include dev->ap we now don't have
to add parameters however just clean them up. Also add data_xfer methods
to the existing drivers except ata_piix (which is in the other block of
patches). If you reject the piix one just add a data_xfer to it...

Signed-off-by: Alan Cox <alan@redhat.com>
Signed-off-by: Jeff Garzik <jeff@garzik.org>