ASoC: dt-bindings: rockchip: i2s-tdm: Drop rockchip,cru property

This property was only needed for a driver hack, which we can
remove. Since the bindings were not in any kernel release yet, we
are able to just drop the property instead of silently accepting
and ignoring it.
Signed-off-by: Nicolas Frattaroli <frattaroli.nicolas@gmail.com>
Reviewed-by: Heiko Stuebner <heiko@sntech.de>
Message-Id: <20211016105354.116513-3-frattaroli.nicolas@gmail.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

Documentation/devicetree/bindings/sound/rockchip,i2s-tdm.yaml

@@ -82,12 +82,6 @@ properties:
         - tx-m
         - rx-m
 
-  rockchip,cru:
-    $ref: /schemas/types.yaml#/definitions/phandle
-    description:
-      The phandle of the cru.
-      Required if neither trcm-sync-tx-only nor trcm-sync-rx-only are specified.
-
   rockchip,grf:
     $ref: /schemas/types.yaml#/definitions/phandle
     description:
@@ -144,15 +138,6 @@ required:
   - rockchip,grf
   - "#sound-dai-cells"
 
-allOf:
-  - if:
-      properties:
-        rockchip,trcm-sync-tx-only: false
-        rockchip,trcm-sync-rx-only: false
-    then:
-      required:
-        - rockchip,cru
-
 additionalProperties: false
 
 examples:
@@ -177,7 +162,6 @@ examples:
             resets = <&cru SRST_M_I2S1_8CH_TX>, <&cru SRST_M_I2S1_8CH_RX>;
             reset-names = "tx-m", "rx-m";
             rockchip,trcm-sync-tx-only;
-            rockchip,cru = <&cru>;
             rockchip,grf = <&grf>;
             #sound-dai-cells = <0>;
             pinctrl-names = "default";