Change in coreboot[master]: console: Allow VPD to disable an otherwise enabled coreboot console

[Patrick Georgi (Code Review)]

Hello build bot (Jenkins), Greg Edelston, Dossym Nurmukhanov,

I'd like you to reexamine a change. Please visit

https://review.coreboot.org/c/coreboot/+/45208

to look at the new patch set (#2).

Change subject: console: Allow VPD to disable an otherwise enabled coreboot console
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console: Allow VPD to disable an otherwise enabled coreboot console

With VPD compiled in, no output is sent to the serial console if
VPD_RO has an entry `disable_serial` set to 1.

This allows using an image for both deployment and testing scenarios
with only the VPD entry modified to toggle (the typically slow)
serial console.

By looking for a positive value in an as-yet undefined VPD entry the
change is transparent: the behavior doesn't change at all unless the
entry is added.

BUG=b:151346403
BRANCH=none
TEST=Taking a Chrome OS config for google/eve, it behaves as expected
with no entry present and both entry states (1, 0 - everything else
falls back to 0) with negligible performance loss.

Change-Id: I4f1f5c45e5ea889176d04e0db438ca2aa7c536ee
Signed-off-by: Patrick Georgi 
---
M src/console/init.c
1 file changed, 23 insertions(+), 1 deletion(-)

git pull ssh://review.coreboot.org:29418/coreboot refs/changes/08/45208/2