Add an optional routine to translate the device path types into a string for display. TEST=Build and run on Galileo Change-Id: Iea5d0a2430d9a8546105324e2beda0955210dca9 Signed-off-by: Lee Leahy <leroy.p.leahy@intel.com> Reviewed-on: https://review.coreboot.org/13715 Tested-by: build bot (Jenkins) Reviewed-by: Martin Roth <martinroth@google.com>