dereg_irqs and dereg_ioat are needed by external functions. Let's
rename and export both of them in s390-pci-inst.h.
Signed-off-by: NYi Min Zhao <zyimin@linux.vnet.ibm.com>
Reviewed-by: NPierre Morel <pmorel@linux.vnet.ibm.com>
Signed-off-by: NCornelia Huck <cornelia.huck@de.ibm.com>