s390/pci: CHSC PCI support for error and availability events

Add CHSC store-event-information support for PCI (notfication type 2)
and report error and availability events to the PCI architecture layer.

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