Allow retrieving accessory detection reference on

Merge series from "Nícolas F. R. A. Prado" <nfraprado@collabora.com>:

This series enables the MT8188-MT6359 sound driver to retrieve the
MT6359 ACCDET sound component from a mediatek,accdet DT property, which
allows detecting jack insertion/removal.

Patch 1 describes the new property in the binding. Patch 2 implements
the sound component retrieval in the common MTK soundcard driver. Patch
4 updates the MT8188-MT6359 sound driver to register the audio jack and
initialize the ACCDET driver for detection, if the property is present.

Patch 3 adds a stub to prevent a linker failure in case the
MT6359-ACCDET config is disabled.

Tested on the Genio 700 EVK board.