powerpc: Fix build without CONFIG_PCI

Commit fea80311a939a746533a6d7e7c3183729d6a3faf
"iomap: make IOPORT/PCI mapping functions conditional"

Broke powerpc build without CONFIG_PCI as we would still define
pci_iomap(), which overlaps with the new empty inline in the headers.

Make our implementation conditional on CONFIG_PCI

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

arch/powerpc/kernel/iomap.c

@@ -117,6 +117,7 @@ void ioport_unmap(void __iomem *addr)
 EXPORT_SYMBOL(ioport_map);
 EXPORT_SYMBOL(ioport_unmap);
 
+#ifdef CONFIG_PCI
 void __iomem *pci_iomap(struct pci_dev *dev, int bar, unsigned long max)
 {
 	resource_size_t start = pci_resource_start(dev, bar);
@@ -143,6 +144,7 @@ void pci_iounmap(struct pci_dev *dev, void __iomem *addr)
 		return;
 	iounmap(addr);
 }
+#endif /* CONFIG_PCI */
 
 EXPORT_SYMBOL(pci_iomap);
 EXPORT_SYMBOL(pci_iounmap);