Change in coreboot[master]: console/printk: Add console_mutex

[Raul Rangel (Code Review)]

Attention is currently required from: Julius Werner, Rob Barnes.
Hello Julius Werner, Rob Barnes,

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

https://review.coreboot.org/c/coreboot/+/58981

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

Change subject: console/printk: Add console_mutex
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console/printk: Add console_mutex

Cooperative multitasking has only been used in ramstage. ramstage has
spin locks enabled, while romstage and earlier don't. This means we
can't rely on the console spin lock. This change adds a console mutex
so printing can work correctly between threads in romstage.

BUG=b:179699789
TEST=Start a thread in romstage and verify console output is not garbled

Signed-off-by: Raul E Rangel 
Change-Id: I5858bb18723f32f6b1e6ef0ed31906d7c79d3fec
---
M src/console/printk.c
1 file changed, 4 insertions(+), 0 deletions(-)

git pull ssh://review.coreboot.org:29418/coreboot refs/changes/81/58981/2