[SeaBIOS] PCI device path?

[Kevin O'Connor]

Hi Gleb,

Did you have any thoughts on how to build the PCI device path for the
bootprio_find_X functions?

I suppose we could keep an "int parentbus[256]" and fill it with info
on the parent info of every PCI bus.  Then the build_pci_path()
function could reconstruct the path of buses back to the root.

As I understand it there could be three types of PCI buses we could
run into - the root bus 0, a pci-to-pci bridge, or a non bus 0 root
bus.

-Kevin