hw/acpi/viot: rename build_pci_range_node() to enumerate_pci_host_bridges()

hw/acpi/viot: rename build_pci_range_node() to enumerate_pci_host_bridges()

This is in preparation for separating out the VIOT ACPI table build from the
PCI host bridge numeration.

Signed-off-by: Mark Cave-Ayland <mark.cave-ayland@ilande.co.uk>
Reviewed-by: Ani Sinha <ani@anisinha.ca>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Message-Id: <20220525173232.31429-2-mark.cave-ayland@ilande.co.uk>
Reviewed-by: Jean-Philippe Brucker <jean-philippe@linaro.org>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>