s390x/pci: dynamically allocate iommu

s390x/pci: dynamically allocate iommu

When initializing a PCI device, an address space is required during PCI
core initialization and before the call to the embedding object hotplug
callback. To provide this AS, we allocate a S390PCIIOMMU object
containing this AS. Initialization of S390PCIIOMMU object is done
before the PCI device is completely created. So that we cannot
associate the IOMMU with the device at the moment. To track the IOMMU
object, we use g_hash functions with the PCI device's bus address as a
key to provide an array of pointers indexed by the PCI device's devfn
to the allocated IOMMU.

Signed-off-by: Yi Min Zhao <zyimin@linux.vnet.ibm.com>
Reviewed-by: Pierre Morel <pmorel@linux.vnet.ibm.com>
Signed-off-by: Cornelia Huck <cornelia.huck@de.ibm.com>