Change in coreboot[master]: mb/google/brya: Enable BT offload

[Tim Wawrzynczak (Code Review)]

Attention is currently required from: Sugnan Prabhu S.
Tim Wawrzynczak has posted comments on this change. ( https://review.coreboot.org/c/coreboot/+/55180 )

Change subject: mb/google/brya: Enable BT offload
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Patch Set 10:

(1 comment)

Patchset:

PS10: 
Sugnan, since this is updating the SoC chip config, there is an override-able function for this already, mainboard_update_soc_chip_config().

Do you mind splitting this one into two patches?
1) Add this function to the baseboard mainboard.c
```
void mainboard_update_soc_chip_config(struct soc_intel_alderlake_config *config)
{
       variant_update_soc_chip_config(config);
}

__weak variant_update_soc_chip_config(struct soc_intel_alderlake_config *config)
{
       /* default implementation does nothing */
}
```
and baseboard/variants.h
2) A patch to add variant_update_soc_chip_config to brya0 like:
```
void variant_update_soc_chip_config(struct soc_intel_alderlake_config *config)
{
      config->CnviBtAudioOffload = fw_config_probe(FW_CONFIG(AUDIO, MAX98373_ALC5682_SNDW)) ? 1 : 0;
}
```

then other variants can also easily update their chip config to handle any similar situations

WDYT?