device/pci: Declare pcidev_path_on_bus()

It is recommended to never reference PCI busses
using a static number. There is exception with
OPROM execution, where we want to translate the
bus number captured from the actual IO operation
into a matching device node in the devicetree.

Change-Id: I733c645ac5581c000b4cd6cdc05829cd039324d5
Signed-off-by: Kyösti Mälkki <kyosti.malkki@gmail.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/34077
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Patrick Georgi <pgeorgi@google.com>

src/include/device/device.h

@@ -288,6 +288,7 @@ DEVTREE_CONST struct device *dev_bus_each_child(const struct bus *parent,
 DEVTREE_CONST struct device *pcidev_path_behind(const struct bus *parent,
 		pci_devfn_t devfn);
 DEVTREE_CONST struct device *pcidev_path_on_root(pci_devfn_t devfn);
+DEVTREE_CONST struct device *pcidev_path_on_bus(unsigned int bus, pci_devfn_t devfn);
 DEVTREE_CONST struct device *pcidev_on_root(uint8_t dev, uint8_t fn);
 DEVTREE_CONST struct bus *pci_root_bus(void);