dt-bindings: display: st,stm32-dsi: Remove unnecessary fields

"#address-cells" and "#size-cells" are two properties that are not
mandatory. For instance, the DSI could refer to a bridge outside the scope
of the node rather than include a 'panel@0' subnode. By doing so, address
and size fields become then unnecessary, creating a warning at build time.

Signed-off-by: Raphael Gallais-Pou <[e-mail]>
Acked-by: Conor Dooley <[e-mail]>
Reviewed-by: Marek Vasut <[e-mail]>
Signed-off-by: Alexandre Torgue <[e-mail]>

Documentation/devicetree/bindings/display/st,stm32-dsi.yaml

···
                   - const: 2
 
 required:
-  - "#address-cells"
-  - "#size-cells"
   - compatible
   - reg
   - clocks