ASoC: dt-bindings: renesas,rsnd: add post-init-providers property

At least if rsnd is using DPCM connection on Audio-Graph-Card2,
fw_devlink might doesn't have enough information to break the cycle
(Same problem might occur with Multi-CPU/Codec or Codec2Codec).
In such case, rsnd driver will not be probed.
Add post-init-providers support to break the link cycle.

Signed-off-by: Kuninori Morimoto <[e-mail]>
Reviewed-by: Rob Herring (Arm) <[e-mail]>
Link: https://patch.msgid.link/[e-mail]
Signed-off-by: Mark Brown <[e-mail]>

Documentation/devicetree/bindings/sound/renesas,rsnd.yaml

···
     description: List of necessary clock names.
     # details are defined below
 
+  post-init-providers:
+    description: At least if rsnd is using DPCM connection on Audio-Graph-Card2,
+      fw_devlink might doesn't have enough information to break the cycle. rsnd
+      driver will not be probed in such case. Same problem might occur with
+      Multi-CPU/Codec or Codec2Codec.
+
   # ports is below
   port:
     $ref: audio-graph-port.yaml#/definitions/port-base