Add test to match struct device with pci_devfn_t

Add a function to test if pci_devfn_t matches with a device
instance of struct device, by comparing bus:dev.fn.

Change-Id: Ic6c3148ac62c7183246d83302ee504b17064c794
Signed-off-by: Kyösti Mälkki <kyosti.malkki@gmail.com>
Reviewed-on: http://review.coreboot.org/3474
Tested-by: build bot (Jenkins)
Reviewed-by: Aaron Durbin <adurbin@google.com>

src/device/pci_device.c

@@ -1053,6 +1053,19 @@ device_t pci_probe_dev(device_t dev, struct bus *bus, unsigned devfn)
 	return dev;
 }
 
+/**
+ * Test for match between romstage and ramstage device instance.
+ *
+ * @param dev Pointer to the device structure.
+ * @param sdev Simple device model identifier, created with PCI_DEV().
+ * @return Non-zero if bus:dev.fn of device matches.
+ */
+unsigned int pci_match_simple_dev(device_t dev, pci_devfn_t sdev)
+{
+	return dev->bus->secondary == PCI_DEV2SEGBUS(sdev) &&
+			dev->path.pci.devfn == PCI_DEV2DEVFN(sdev);
+}
+
 /**
  * Scan a PCI bus.
  *