[coreboot-gerrit] Change in coreboot[master]: pciexp_device: Rewrite LTR configuration

[Nico Huber (Code Review)]

Attention is currently required from: Furquan Shaikh, Michael Niewöhner, Kyösti Mälkki, Patrick Rudolph, Aaron Durbin.
Nico Huber has posted comments on this change. ( https://review.coreboot.org/c/coreboot/+/51328 )

Change subject: pciexp_device: Rewrite LTR configuration
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Patch Set 2:

(1 comment)

File src/device/pciexp_device.c:

https://review.coreboot.org/c/coreboot/+/51328/comment/8a8088c4_df2717b7 
PS1, Line 130: _
> nit: from a cursory glance, prefixing static function names with `_` isn't very common in coreboot;  […]

It's not about static functions. I used the _ prefix here when I needed a
basic version of the function that takes the `cap` offset as an argument.

Looking at the current implementation, the only name clash is with
pci_exp_enable_ltr(). So I could rename the first two functions here
without hassle. If that is preferred?