[coreboot] Unifying IO accessor macros

[Stefan Reinauer]

* Julius Werner <jwerner at chromium.org> [150218 00:12]:
> I'd like to propose an API change/cleanup for a long-standing problem
> with architecture-independent code that people have hit and privately
> discussed/cursed multiple times already, but no one really had time to
> make the big change/fix yet. (Some earlier discussion among Chromium
> people about this is available at http://crbug.com/451388 )

[..]

I think nobody disagrees that type checking is a bad idea here.
It was a mistake to let type checking free versions of these accessors
slip into the tree into the first place.

The second part is a little bit more prone to personal preferences.
- Using 8 / 16 / 32 / 64 for data size is more explicit that b / w / l / q
- (addr, val) is more aligned with other APIs in coreboot
- Using the Linux API as a standard will make it easier for people to
  switch between code bases, and thus is a lot less error prone
- Using the Linux API makes it easier to share code with other projects.
  such as u-boot, Linux, libpayload based projects

Since there is no clear winner, I would like to ask you to participate
in a poll to measure what people would prefer:

 http://doodle.com/3dwbudycrypg9xyf

Stefan