Adjust usage of rt5682(s) power supply properties

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

This series sets straight the usage of power supply properties for the
rt5682 and rt5682s audio codecs.

These properties were already being used by sc7180-trogdor.dtsi (and
derived DTs like sc7180-trogdor-kingoftown.dtsi).

We start by documenting the power supplies that are already in use and
then add few others that were missing to the bindings.

Then we update the drivers to also support the new supplies.

Finally we update the trogdor DTs so they have the newly added but
required supplies and remove a superfluous one that was causing
warnings.