s390/pci: cleanup hotplug code

Provide wrappers for the [de]configure operations, add some error
handling, and use pci_scan_slot instead of pci_scan_single_device.

Reviewed-by: Gerald Schaefer <gerald.schaefer@de.ibm.com>
Signed-off-by: Sebastian Ott <sebott@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

diff --cc arch/s390/include/asm/pci.h
Simple merge

diff --cc arch/s390/pci/pci.c
Simple merge

diff --cc drivers/pci/hotplug/s390_pci_hpc.c
Simple merge