ASoC: dt-bindings: Document audio OF graph dai-tdm-slot-num dai-tdm-slot-width props

Document dai-tdm-slot-num and dai-tdm-slot-width props as those are
parsed by simple graph card and may therefore appear in audio OF graph
node.
Signed-off-by: Marek Vasut <marex@denx.de>
Reviewed-by: Rob Herring <robh@kernel.org>
Link: https://lore.kernel.org/r/20220927185359.294322-1-marex@denx.deSigned-off-by: Mark Brown <broonie@kernel.org>

Documentation/devicetree/bindings/sound/audio-graph-port.yaml

@@ -74,6 +74,12 @@ patternProperties:
       convert-sample-format:
         $ref: "/schemas/sound/dai-params.yaml#/$defs/dai-sample-format"
 
+      dai-tdm-slot-num:
+        description: Number of slots in use.
+        $ref: /schemas/types.yaml#/definitions/uint32
+      dai-tdm-slot-width:
+        description: Width in bits for each slot.
+        $ref: /schemas/types.yaml#/definitions/uint32
       dai-tdm-slot-width-map:
         description: Mapping of sample widths to slot widths. For hardware
           that cannot support a fixed slot width or a slot width always