[L] Change in coreboot[master]: util/amdfwtool: Deal with psp position in flash offset directly

[Christopher Meis (Code Review)]

Attention is currently required from: Bao Zheng, Jason Glenesk, Raul Rangel, Jason Nien, Matt DeVillier, Arthur Heymans, Martin Roth, Fred Reitberger, Marvin Drees, Karthik Ramasubramanian, Felix Held.

Christopher Meis has posted comments on this change. ( https://review.coreboot.org/c/coreboot/+/69852 )

Change subject: util/amdfwtool: Deal with psp position in flash offset directly
......................................................................

Patch Set 4:

(1 comment)

File src/soc/amd/common/Makefile.inc:

https://review.coreboot.org/c/coreboot/+/69852/comment/fc12b8e2_200fb00e 
PS4, Line 25: $(call int-subtract, 0xffffffff $(CONFIG_ROM_SIZE)) 1 $(CONFIG_AMD_FWM_POSITION))
> "The PSP really only cares about flash offsets, not x86 mmap offsets." […]

This also is not exactly correct.

When looking for the EFS location, the PSP only cares about flash offsets.
In EFT, again, addresses to PSP and BIOS directories are set in flash offsets.

PSP and BIOS directory headers have a indicator to provide information about address mode to expect from each entry. Entries inherit this information if not overwritten by entry configuration from the outside/user.