[XL] Change in coreboot[main]: mb/purism/librem_jsl: Add support for Librem 11

[Matt DeVillier (Code Review)]

Attention is currently required from: Angel Pons, Felix Held, Jonathon Hall, Martin L Roth.

Matt DeVillier has posted comments on this change. ( https://review.coreboot.org/c/coreboot/+/78343?usp=email )

Change subject: mb/purism/librem_jsl: Add support for Librem 11
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Patch Set 2: Code-Review+1

(2 comments)

Patchset:

PS1:
> Write-up about how the memory info was extracted from UEFI firmware: https://puri. […]

very nice!

Patchset:

PS2: 
don't see any major issues, but if you do anticipate having another JSL variant in the future, you might want to go ahead and set up the L11 as a proper variant, even thought it's the only one currently. google/drallion is an example of the single variant setup