[S] Change in coreboot[master]: mb/starlabs/starbook: Add ramtop_cmos_offset

[Nico Huber (Code Review)]

Attention is currently required from: Sean Rhodes.

Nico Huber has posted comments on this change. ( https://review.coreboot.org/c/coreboot/+/74432 )

Change subject: mb/starlabs/starbook: Add ramtop_cmos_offset
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Patch Set 2:

(2 comments)

Patchset:

PS2: 
Was this tested with/without USE_OPTION_TABLE enabled?

File src/mainboard/starlabs/starbook/cmos.layout:

https://review.coreboot.org/c/coreboot/+/74432/comment/796b5b89_ff3fde08 
PS2, Line 42: 800
The ramstop feature doesn't seem to use the option table API and I don't see
anything that would update the option table checksum. So, should this be outside
the checksum region?

(I also don't understand why it's stored at a hardcoded location even with
USE_OPTION_TABLE enabled.)