drivers/xen: Use never-managed version of pci_intx()

drivers/xen: Use never-managed version of pci_intx()

pci_intx() is a hybrid function which can sometimes be managed through
devres. To remove this hybrid nature from pci_intx(), it is necessary to
port users to either an always-managed or a never-managed version.

xen enables its PCI device with pci_enable_device(). Thus, it needs the
never-managed version.

Replace pci_intx() with pci_intx_unmanaged().

Link: https://lore.kernel.org/r/20241209130632.132074-4-pstanner@redhat.com
Signed-off-by: Philipp Stanner <pstanner@redhat.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Acked-by: Juergen Gross <jgross@suse.com>