[S] Change in coreboot[main]: ec/google/chromeec: Add debug timestamp for host EC commands

[Subrata Banik (Code Review)]

Attention is currently required from: Boris Mittelberg, Caveh Jalali, Jayvik Desai, Julius Werner, Kapil Porwal, Paul Menzel.

Subrata Banik has posted comments on this change by Jayvik Desai. ( https://review.coreboot.org/c/coreboot/+/85326?usp=email )

Change subject: ec/google/chromeec: Add debug timestamp for host EC commands
......................................................................

Patch Set 11:

(1 comment)

File src/ec/google/chromeec/ec_lpc.c:

https://review.coreboot.org/c/coreboot/+/85326/comment/2edde0d2_fe984ef1?usp... :
PS9, Line 286: printk
> > Please call stopwatch_tick() before accessing sw.current.
>
> Added
> > The absolute timestamp isn't really meant to be accessed at all. Is there a reason to print it here (rather than just the duration)? coreboot timers aren't guaranteed to start at 0 at boot, so absolute timer values are basically meaningless anyway.
>
> you are right, the timestamps doesn't make much sense, the only reason it's there is because some external team required it at some point.
>
> Removed.

I still believe adding entry inside cbmem is better as this will solve two problems

1. Allow partners to measure the time takes for each host cmd w/o any additional parsing

2. Allow platform team like us to debug boot regression easilly, we just need to enable some Kconfig to verbose the EC host cmd telemetry data.