hw/pci: Export pci_device_get_iommu_bus_devfn() and return bool

hw/pci: Export pci_device_get_iommu_bus_devfn() and return bool

Returns true if PCI device is aliased or false otherwise. This will be
used in following patch to determine if a PCI device is under a PCI
bridge.

Signed-off-by: Zhenzhong Duan <zhenzhong.duan@intel.com>
Reviewed-by: Eric Auger <eric.auger@redhat.com>
Reviewed-by: Nicolin Chen <nicolinc@nvidia.com>
Reviewed-by: Yi Liu <yi.l.liu@intel.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Link: https://lore.kernel.org/qemu-devel/20260106061304.314546-5-zhenzhong.duan@intel.com
Signed-off-by: Cédric Le Goater <clg@redhat.com>