Hifiberry DAC2 HD not working with 3.702 on Pi 4 - mixer type UNDEFINED

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HiFiBerry DAC on Volumio OS

Dear Volumionauts, Problem We received numerous reports from our community about HiFiBerry DACs lagging behind kernel upstream compatibility and progression. Starting from kernel 6.0 there is an effort of fixing various clock management code across the kernel core and the device tree. Most of the DACs vendors doing their best to keep-up with the changes, a handful of the vendors like HiFiBerry choose to stay on kernel 5.5 and skip forward to the currently maintained - 6.6. Discovery Volumio is…