[S] Change in coreboot[master]: ec/google/chromeec: Add retimer flag for mux device

[Caveh Jalali (Code Review)]

Attention is currently required from: Prashant Malani, Boris Mittelberg.

Caveh Jalali has posted comments on this change. ( https://review.coreboot.org/c/coreboot/+/71663 )

Change subject: ec/google/chromeec: Add retimer flag for mux device
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Patch Set 1:

(1 comment)

Commit Message:

https://review.coreboot.org/c/coreboot/+/71663/comment/44058bb8_5f73d173 
PS1, Line 10: instead of assuming that all ports have retimers
> TimW had me add modifications to brya0, just to ensure things are build tested, but those should sti […]

i was thinking more along the lines of the kernel assuming there's
a retimer based on "mode-switch". such code would need to
change to only make that determination based on the
presence of "retimer-switch".

we are making a semantic change to "mode-switch" here, so
we should be clear about whether consumers of this property
are impacted.
if we're reasonably confident that no code depends on the
original definition, i guess it's OK to "clarify" the
definition.