s390/pci: add PCI access type and length to error records

Currently when a PCI instruction returns a non-zero condition code it
can be very hard to tell from the s390dbf logs what kind of instruction
was executed. In case of PCI memory I/O (MIO) instructions it is even
impossible to tell if we attempted a load, store or block store or how
large the access was because only the address is logged.

Improve this by adding an indicator byte for the instruction type to the
error record and also store the length of the access for MIO
instructions where this can not be deduced from the request.

We use the following indicator values:
 - 'l': PCI load
 - 's': PCI store
 - 'b': PCI store block
 - 'L': PCI load (MIO)
 - 'S': PCI store (MIO)
 - 'B': PCI store block (MIO)
 - 'M': MPCIFC
 - 'R': RPCIT

Reviewed-by: Matthew Rosato <mjrosato@linux.ibm.com>
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>