fpga/dfl-pci.c: Replace deprecated PCI functions

fpga/dfl-pci.c: Replace deprecated PCI functions

pcim_iomap_regions() and pcim_iomap_table() have been deprecated by the
PCI subsystem in commit e354bb84a4c1 ("PCI: Deprecate
pcim_iomap_table(), pcim_iomap_regions_request_all()").

Port dfl-pci.c to the successor, pcim_iomap_region().

Consistently, replace pcim_iounmap_regions() with pcim_iounmap_region().

Link: https://lore.kernel.org/r/20241016094911.24818-5-pstanner@redhat.com
Signed-off-by: Philipp Stanner <pstanner@redhat.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Andy Shevchenko <andy@kernel.org>
Acked-by: Xu Yilun <yilun.xu@intel.com>