device/pci: Reduce scope of dev_find_slot()

We only keep it around because soc/intel debugging
still depends on it.

Change-Id: I3ea37c097bbcc3cf5c0574c7d727eae4f5bee307
Signed-off-by: Kyösti Mälkki <kyosti.malkki@gmail.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/34084
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Arthur Heymans <arthur@aheymans.xyz>

src/device/device_const.c

@@ -34,7 +34,8 @@ DEVTREE_CONST struct device * DEVTREE_CONST all_devices = &dev_root;
  * @param devfn A device/function number.
  * @return Pointer to the device structure (if found), 0 otherwise.
  */
-DEVTREE_CONST struct device *dev_find_slot(unsigned int bus,
+
+static DEVTREE_CONST struct device *dev_find_slot(unsigned int bus,
 						unsigned int devfn)
 {
 	DEVTREE_CONST struct device *dev, *result;