dt-bindings: display: novatek,nt36672a: Fix unevaluated properties warning

With 'unevaluatedProperties' support enabled, the novatek,nt36672a
binding has a new warning:

Documentation/devicetree/bindings/display/panel/novatek,nt36672a.example.dt.yaml: panel@0: Unevaluated properties are not allowed ('vddi0-supply', '#address-cells', '#size-cells' were unexpected)

Based on dts files, 'vddi0-supply' does appear to be the correct name.
Drop '#address-cells' and '#size-cells' which aren't needed.

Signed-off-by: Rob Herring <robh@kernel.org>
Acked-by: Sam Ravnborg <sam@ravnborg.org>
Link: https://lore.kernel.org/r/20211221125125.1194554-1-robh@kernel.org