util: Add hda-decoder

util: Add hda-decoder

This tool helps take off the burden of manually decoding default
configuration registers. Using decoded values can make code more
self-documenting compared to shrouding it with magic numbers.

This is also written as a module which allows easy integration with
other tools written in Go (e.g. autoport).

Change-Id: Ib4fb652e178517b2b7aceaac8be005c5b2d3b03e
Signed-off-by: Nicholas Sudsgaard <devel+coreboot@nsudsgaard.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/80470
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Felix Singer <service+coreboot-gerrit@felixsinger.de>
Reviewed-by: Michael Niewöhner <foss@mniewoehner.de>