* Intel High-definition Audio

Configuration is set using 'verbs' which are blocks of 16 bytes of data each
with a different purpose, a little like a simple instruction set.

Top-level node
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Required properties:
- compatible: "intel,hd-audio"
- beep-verbs: list of verbs to send for a beep

Optional properties
- intel,beep-nid: Node ID to use for beep (will be detected if not provided)

Required subnodes:
- codecs: Contains a list of codec nodes


* Codec nodes

Required properties:
- vendor-id: 16-bit vendor ID for audio codec
- device-id: 16-bit device ID for audio codec
- verbs: List of verbs, each 4 cells in length