Change in coreboot[master]: ChromeOS: Add legacy mainboard_ec_running_ro()

[Julius Werner (Code Review)]

Attention is currently required from: Tim Wawrzynczak, Kyösti Mälkki.
Julius Werner has posted comments on this change. ( https://review.coreboot.org/c/coreboot/+/58896 )

Change subject: ChromeOS: Add legacy mainboard_ec_running_ro()
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Patch Set 7:

(2 comments)

File src/include/bootmode.h:

https://review.coreboot.org/c/coreboot/+/58896/comment/d485a440_e56fc625 
PS7, Line 17: bool mainboard_ec_running_ro(void);
> the EC is trusted when it is running RO, it is untrusted when running RW, so conceptually they are t […]

(see https://review.coreboot.org/c/coreboot/+/58896/7/src/vendorcode/google/chrom..., they're not always equivalent)

File src/mainboard/google/butterfly/chromeos.c:

https://review.coreboot.org/c/coreboot/+/58896/comment/b1048ff5_6e521971 
PS5, Line 14: void fill_lb_gpios(struct lb_gpios *gpios)
> I am having trouble finding the schematics for butterly, I will keep digging.

Butterfly did not use a Chrome EC, so I'm pretty sure it didn't have that line.