i.e. alignment, max_address, max_iosize and segsize (only max_address is
thought to have an negative impact regarding this issue though), after
calling ata_dmainit() either directly or indirectly so these values have
no effect or at least no effect on the DMA tags and the defaults are used
for the latter instead. So change the drivers to set these parameters
up-front and ata_dmainit() to honor them.
Reviewd by: mav
MFC after: 1 month
1510a2b019