[M] Change in coreboot[master]: src/device: Clear lane error status

[Jonathan Zhang (Code Review)]

Attention is currently required from: Wilson Chou, Marc Jones, Nico Huber, Ryback Hung, Johnny Lin, Tim Wawrzynczak, Shuming Chu (Shuming).

Jonathan Zhang has posted comments on this change. ( https://review.coreboot.org/c/coreboot/+/67264 )

Change subject: src/device: Clear lane error status
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Patch Set 2:

(1 comment)

Patchset:

PS2:
> Based on where Wilson has put the call to clear_lane_error_status(), I am guessing that it is the li […]

We need to clear lane error status after (last) link training triggered by coreboot. Otherwise lspci would show (erroneous) lane error when booted from coreboot.
This issue was surfaced on xeon-sp server. We do not know whether it applies to other mainboard, hence added a Kconfig.