esp_codec_dev: Add read/write register methods to the interface (AUD-6326)

[robert-alfaro]

Description

Adding read and write methods to esp_codec_dev to expose to internal driver get/set reg api. This is useful in the BSP layer of code to allow configuring the codecs further.

Related

Testing

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Checklist

Before submitting a Pull Request, please ensure the following:

• 🚨 This PR does not introduce breaking changes.
• All CI checks (GH Actions) pass.
• Documentation is updated as needed.
• Tests are updated or added as necessary.
• Code is well-commented, especially in complex areas.
• Git history is clean — commits are squashed to the minimum necessary.