s390/pci: use physical addresses in DMA tables

The entries in the DMA translation tables for our IOMMU must specify
physical addresses of either the next level table or the final page
to be mapped for DMA. Currently however the code simply passes the
virtual addresses of both. On the other hand we still need to walk the
tables via their virtual addresses so we need to do a phys_to_virt()
when setting the entries and a virt_to_phys() when getting them.
Similarly when passing the I/O translation anchor to the hardware we
must also specify its physical address.

As the DMA and IOMMU APIs we are implementing already use the correct
phys_addr_t type for the address to be mapped let's also thread this
through instead of treating it as just an unsigned long.

Note: this currently doesn't fix a real bug, since virtual addresses
are indentical to physical ones.

Reviewed-by: Pierre Morel <pmorel@linux.ibm.com>
Signed-off-by: Niklas Schnelle <schnelle@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>