[S] Change in coreboot[master]: x86: pci_io_cfg: Make constant unsigned to fix out of bounds shift

[Nico Huber (Code Review)]

Attention is currently required from: Paul Menzel, Angel Pons.

Nico Huber has posted comments on this change. ( https://review.coreboot.org/c/coreboot/+/51292 )

Change subject: x86: pci_io_cfg: Make constant unsigned to fix out of bounds shift
......................................................................

Patch Set 3:

(1 comment)

File src/arch/x86/include/arch/pci_io_cfg.h:

https://review.coreboot.org/c/coreboot/+/51292/comment/1eca6d8f_7a0f551d 
PS1, Line 13: 1UL
> Done

It's a matter of being compatible with coreboot's *current* environment or C
in general. For the latter, it should be `ul` because only then at least 32 bits
are guaranteed.

I don't expect this to change in coreboot ever. However, sticking to C helps
to educate each other so we also don't make mistakes in other projects.

(Btw. did the general discussion if we do this change just for the sake of UBSan
ever settle? There was the argument, that we know how GCC/Clang define the
behavior anyway.)