Change in coreboot[master]: src/arch/ppc64/*: pass FDT address to payload

[Sergii Dmytruk (Code Review)]

Attention is currently required from: Arthur Heymans, Timothy Pearson, Ron Minnich.
Sergii Dmytruk has posted comments on this change. ( https://review.coreboot.org/c/coreboot/+/57084 )

Change subject: src/arch/ppc64/*: pass FDT address to payload
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Patch Set 14:

(2 comments)

Patchset:

PS13:
> Hmm wouldn't a linkerscript symbol shared in early stages, that you then move the cbmem in ramstage  […]

Thought handoff would be a more "correct" solution, but yeah it's just uglier.

File src/arch/ppc64/fdt.h:

https://review.coreboot.org/c/coreboot/+/57084/comment/00a106d6_96e65684 
PS13, Line 9: CBMEM_ID_FDT_ADDRESS
> CBMEM_ID are to be placed in commonlib/include/commonlib/cbmem_id. […]

I thought it's too specific to the platform to put there. Moved.