[PATCH] of/irq: provide int of_irq_parse_and_map_pci wrapper

The pci-rcar driver is enabled for compile tests, and this has
now shown that the driver cannot build without CONFIG_OF,
following the inclusion of f8f2fe7355fb "PCI: rcar: Use new OF
interrupt mapping when possible":

drivers/built-in.o: In function `rcar_pci_map_irq':
:(.text+0x1cc7c): undefined reference to `of_irq_parse_and_map_pci'

As pointed out by Ben Dooks and Geert Uytterhoeven, this is actually
supposed to build fine, which we can achieve if we make the
declaration of of_irq_parse_and_map_pci conditional on CONFIG_OF
and provide an empty inline function otherwise, as we do for
a lot of other of interfaces.

This lets us build the rcar_pci driver again without CONFIG_OF,
which won't work but give us compile time coverage.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Cc: Bjorn Helgaas <bhelgaas@google.com>
Cc: Magnus Damm <redacted>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Ben Dooks <redacted>
Cc: linux-pci@vger.kernel.org
Cc: linux-sh@vger.kernel.org

diff --git a/include/linux/of_pci.h b/include/linux/of_pci.h
index 1a1f5ff..1e29bf4 100644
--- a/include/linux/of_pci.h
+++ b/include/linux/of_pci.h

@@ -7,13 +7,18 @@
 struct pci_dev;
 struct of_phandle_args;
 int of_irq_parse_pci(const struct pci_dev *pdev, struct of_phandle_args *out_irq);
-int of_irq_parse_and_map_pci(const struct pci_dev *dev, u8 slot, u8 pin);
 
 struct device_node;
 struct device_node *of_pci_find_child_device(struct device_node *parent,
 					     unsigned int devfn);
 int of_pci_get_devfn(struct device_node *np);
 int of_pci_parse_bus_range(struct device_node *node, struct resource *res);
+#ifdef CONFIG_OF
+int of_irq_parse_and_map_pci(const struct pci_dev *dev, u8 slot, u8 pin);
+#else
+static inline int
+of_irq_parse_and_map_pci(const struct pci_dev *dev, u8 slot, u8 pin) { return 0; }
+#endif
 
 #if defined(CONFIG_OF) && defined(CONFIG_PCI_MSI)
 int of_pci_msi_chip_add(struct msi_chip *chip);