ASoC: dt-bindings: wlf,wm8962: Convert to json-schema

Convert the Wolfson WM8962 Ultra-Low Power Stereo CODEC Device Tree
binding documentation to json-schema.

Add missing *-supply and port properties.
Update the example.

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Acked-by: Charles Keepax <ckeepax@opensource.cirrus.com>
Reviewed-by: Rob Herring <robh@kernel.org>
Link: https://lore.kernel.org/r/b0868d2f62fd57499c79d96298e99e5f9e4fbc76.1634565154.git.geert+renesas@glider.be


Signed-off-by: Mark Brown <broonie@kernel.org>