Change in coreboot[master]: mb/{asrock,intel,siemens}: Define `.chipset_lockdown`

[Nico Huber (Code Review)]

Attention is currently required from:  Felix Singer, Benjamin Doron, Subrata Banik.
Nico Huber has posted comments on this change. ( https://review.coreboot.org/c/coreboot/+/50053 )

Change subject: mb/{asrock,intel,siemens}: Define `.chipset_lockdown`
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Patch Set 6:

(1 comment)

File src/mainboard/siemens/chili/variants/chili/devicetree.cb:

https://review.coreboot.org/c/coreboot/+/50053/comment/a2688abf_4fdc4e90 
PS6, Line 13: 		.chipset_lockdown = CHIPSET_LOCKDOWN_COREBOOT,
> IIRC, we didn't set it on purpose. The coreboot path seemed unfinished […]

Turns out that the LOCKDOWN_FSP path is broken by now (we can't flash
internally anymore with it). I'll give up on upstream security for the
time being. As long as Intel is "contributing", it seems impossible.