ASoC: dt-bindings: nxp, tfa989x: Add vddd-supply property

Add optional vddd-supply property to allow regulator control.

Signed-off-by: Vincent Knecht <vincent.knecht@mailoo.org>
Link: https://lore.kernel.org/r/20210528105101.508254-3-vincent.knecht@mailoo.org


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