PCI: Export pci_pio_to_address() for module use

This interface will be used by PCI host drivers for PIO translation,
export it to support compiling those drivers as kernel modules.

Link: https://lore.kernel.org/r/20210420061723.989-3-jianjun.wang@mediatek.com
Signed-off-by: Jianjun Wang <jianjun.wang@mediatek.com>
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Acked-by: Bjorn Helgaas <bhelgaas@google.com>

drivers/pci/pci.c

@@ -4052,6 +4052,7 @@ phys_addr_t pci_pio_to_address(unsigned long pio)
 
 	return address;
 }
+EXPORT_SYMBOL_GPL(pci_pio_to_address);
 
 unsigned long __weak pci_address_to_pio(phys_addr_t address)
 {