Change in coreboot[master]: Documentation/RFC: Generalize PCI support in coreboot

[Shelley Chen (Code Review)]

Attention is currently required from:  Felix Singer, Nico Huber, Furquan Shaikh, Martin Roth, Tim Wawrzynczak, Paul Menzel, Angel Pons, Julius Werner, Kyösti Mälkki, Yu-Ping Wu, Jianjun Wang.
Shelley Chen has posted comments on this change. ( https://review.coreboot.org/c/coreboot/+/57861 )

Change subject: Documentation/RFC: Generalize PCI support in coreboot
......................................................................

Patch Set 12:

(1 comment)

File Documentation/RFC/pci_config_access.md:

https://review.coreboot.org/c/coreboot/+/57861/comment/bc8dd8de_b47f7ffe 
PS12, Line 125: ### Specifying MMIO support for PCI devices that don't support ECAM
              : 
              : We’ll need to be able to distinguish between a platform using the ECAM access
              : method and any other MMIO access mechanism.  For devices that support ECAM, they
              : would have to select the `ECAM_MMONCF_SUPPORT` config.  For devices that don't
              : support ECAM and would still need MMIO support, they would need to explictly
              : select the `NO_ECAM_MMCONF_SUPPORT` config and include the `pci_mmio_cfg.h'
              : header file in their platform-specific source.
> +1 to what Nico said. […]

Sorry, I'll try to fix up the example so it's not confusing.

Agree with Nico/Angel.  This just defines the software support.  It seems like your hardware supports both access mechanisms?  If you prefer the non-ECAM method due to space constraints, it's fine to reflect this in your pci_map_bus() function implementation.