Change in coreboot[master]: [RFC] CBMEM: Have INIT_HOOKS in every stage

[Arthur Heymans (Code Review)]

Attention is currently required from: Hung-Te Lin, Jason Glenesk, Raul Rangel, Marshall Dawson, Tim Wawrzynczak, Christian Walter, Kyösti Mälkki, Andrey Petrov, Fred Reitberger, Yu-Ping Wu, Felix Held.
Arthur Heymans has posted comments on this change. ( https://review.coreboot.org/c/coreboot/+/63375 )

Change subject: [RFC] CBMEM: Have INIT_HOOKS in every stage
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Patch Set 9: Code-Review+2

(1 comment)

File src/include/cbmem.h:

https://review.coreboot.org/c/coreboot/+/63375/comment/db9b594c_b692640a 
PS8, Line 123: CBMEM_CREATION_HOOK
> Can you add some documentation on when I would use `CBMEM_CREATION_HOOK` vs `CBMEM_READY_HOOK`?

I think the gist is the following:
- Use CBMEM_CREATION_HOOK for code that needs to be run when cbmem is initialized for the first time. An example would be code that migrates data from cache as ram to memory.
- Use CBMEM_READY_HOOK for code that needs to run in all stages that have cbmem, e.g. cbmem console needs to get the console from previous stages.