Change in coreboot[master]: mb/google/guybrush: Override I2C3 pad configuration

[Karthik Ramasubramanian (Code Review)]

Attention is currently required from: Jason Glenesk, Raul Rangel, Martin Roth, Marshall Dawson, Felix Held.
Karthik Ramasubramanian has posted comments on this change. ( https://review.coreboot.org/c/coreboot/+/55149 )

Change subject: mb/google/guybrush: Override I2C3 pad configuration
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Patch Set 3:

(1 comment)

File src/mainboard/google/guybrush/variants/baseboard/devicetree.cb:

https://review.coreboot.org/c/coreboot/+/55149/comment/bd8293e5_a93b7aed 
PS3, Line 55: i2c_pad_ctrl_rx_sel
> Hrmm, it would have been nice to group this with the other i2c config: https://source.chromium. […]

I initially thought about adding it to soc_amd_common_i2c_config. Later I realized that this misc pad config applies only to picasso and cezanne. This register set does not exist in stoneyridge.

Also not sure about moving to dw_i2c_bus_config, since that is used in Intel platforms too and they configure the voltage level differently.