macio: handle non-block ATAPI DMA transfers

Currently the macio DMA routines assume that all DMA requests are for read/write
block transfers. This is not always the case for ATAPI, for example when
requesting a TOC where the response is generated directly in the IDE buffer.

Detect these non-block ATAPI DMA transfers (where no lba is specified in the
command) and copy the results directly into RAM as indicated by the DBDMA
descriptor. This fixes CDROM access under MorphOS.

Signed-off-by: Mark Cave-Ayland <mark.cave-ayland@ilande.co.uk>
Signed-off-by: Alexander Graf <agraf@suse.de>