of/irq: Create of_irq_parse_and_map_pci() to consolidate arch code.

Several architectures open code effectively the same code block for
finding and mapping PCI irqs. This patch consolidates it down to a
single function.

Signed-off-by: Grant Likely <grant.likely@linaro.org>
Acked-by: Michal Simek <monstr@monstr.eu>
Cc: Russell King <linux@arm.linux.org.uk>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
diff --git a/drivers/pci/host/pci-mvebu.c b/drivers/pci/host/pci-mvebu.c
index 3a8d01e..07ddb3a 100644
--- a/drivers/pci/host/pci-mvebu.c
+++ b/drivers/pci/host/pci-mvebu.c
@@ -645,18 +645,6 @@
 	return 1;
 }
 
-static int __init mvebu_pcie_map_irq(const struct pci_dev *dev, u8 slot, u8 pin)
-{
-	struct of_phandle_args oirq;
-	int ret;
-
-	ret = of_irq_parse_pci(dev, &oirq);
-	if (ret)
-		return ret;
-
-	return irq_create_of_mapping(&oirq);
-}
-
 static struct pci_bus *mvebu_pcie_scan_bus(int nr, struct pci_sys_data *sys)
 {
 	struct mvebu_pcie *pcie = sys_to_pcie(sys);
@@ -705,7 +693,7 @@
 	hw.private_data   = (void **)&pcie;
 	hw.setup          = mvebu_pcie_setup;
 	hw.scan           = mvebu_pcie_scan_bus;
-	hw.map_irq        = mvebu_pcie_map_irq;
+	hw.map_irq        = of_irq_parse_and_map_pci;
 	hw.ops            = &mvebu_pcie_ops;
 	hw.align_resource = mvebu_pcie_align_resource;