ACPI: PCI: Constify fwnode_handle in acpi_pci_root_remap_iospace()

The fwnode_handle pointer passed into pci_register_io_range() is not
modified, so annotate it as const.

Signed-off-by: Pei Xiao <xiaopei01@kylinos.cn>
Link: https://patch.msgid.link/7ae7866ab8b897253703ecee44c688b6832d49a3.1745552799.git.xiaopei01@kylinos.cn


[ rjw: Subject and changelog edits ]
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>