Refactor PCI configuration register access functions

[rudywasfound]

amd64/pci: tighten up MMCONFIG access handling and consolidate cfg read return values

Motivation

• Apply realloc and MMCONFIG mapping check, limit the number of MCFG regions, unconditionally make config reads return uint32_t, enforce 1/2/4-byte CFGA access and mask I/O widths.

Changes

• amd64/pci: make MMCONFIG accesses more robust and unify config-space returns
• Check realloc and pmap_mapdev_pciecfg return, cap MCFG regions, normalize config read return type to uint32_t, limit/align CFGA sizes, mask I/O transfers.

Signed-off-by: Atiksh Sharma [email protected]

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