s390/pci: enable NEED_DMA_MAP_STATE

The DMA API allows to avoid DMA unmaps because they are NOPs on some
plattforms. But not on s390, so force them.

Signed-off-by: Jan Glauber <jang@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>