[XS] Change in coreboot[main]: mb/google/brox/var/brox: Enable Class-D calibration

[Terry Cheong (Code Review)]

Attention is currently required from: Paul Menzel, Shelley Chen, Subrata Banik.

Terry Cheong has posted comments on this change by Terry Cheong. ( https://review.coreboot.org/c/coreboot/+/82794?usp=email )

Change subject: mb/google/brox/var/brox: Enable Class-D calibration
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Patch Set 7:

(2 comments)

Commit Message:

https://review.coreboot.org/c/coreboot/+/82794/comment/ec4d9253_c51cdab9?usp... :
PS2, Line 10: based
            : on the updated verb table provided by Realtek
> Included the bug and comment number as well.

Done

https://review.coreboot.org/c/coreboot/+/82794/comment/8eb65d4a_1a338ce8?usp... :
PS2, Line 15: TEST=Verify DC offset of speaker amplier is less than 3mV
> How? And what value did you measure?

Actually it is DC offset value of the speaker output pins, we directly pull those out in hardware and measured with multimeter. Added description in the test field.