T520 board now under coreboot 4.19 : UNTESTED

[tlaurion]

coreboot 4.19 just got merged with commit https://github.com/osresearch/heads/commit/3a38ac02e3dbd4de911307a3183c811c8a49611e per merge of https://github.com/osresearch/heads/pull/1312

As of today, t520 board is the only xx20 board not currently having a board owner under #692. Do not flash internally if you do not have an external reprogrammer.

If you have an external reprogrammer, please test and report here to remove this pinned issue.

Direct rom download is at https://output.circle-artifacts.com/output/job/22fc46e9-3423-4743-8549-2a18c48fa3a1/artifacts/0/build/x86/t520-maximized/heads-t520-maximized-v0.2.0-1529-g3a38ac0.rom for 30 days.

Build happened at https://app.circleci.com/pipelines/github/osresearch/heads/576/workflows/23eecb00-6f88-4cf6-934a-49b05a61a65f/jobs/9184