dt-bindings: dma: dma40: Restore disabled-channels

The conversion of the DMA40 binding to YAML omitted the optional
disabled-channels property from the original text binding. The driver still
parses this property, but additionalProperties: false rejects any device
tree using it.

Restore disabled-channels and constrain it to the physical channel range.
Also constrain memcpy-channels to the limits enforced by the driver and
reject duplicate channel entries in both properties.

Fixes: 23fbc87c8a ("dt-bindings: dma: Rewrite ST-Ericsson DMA40 to YAML")
Assisted-by: LLM
Signed-off-by: Linus Walleij <linusw@kernel.org>
Reviewed-by: Rob Herring (Arm) <robh@kernel.org>
Link: https://patch.msgid.link/20260918-dma40-dt-disabled-channels-v1-1-0f691109d8d3@kernel.org
Signed-off-by: Vinod Koul <vkoul@kernel.org>

Documentation/devicetree/bindings/dma/stericsson,dma40.yaml

@@ -140,8 +140,22 @@ properties:
       - description: LCPA (Logical Channel Parameter Address) memory.
       - description: LCLA (Logical Channel Link base Address) memory.
 
+  disabled-channels:
+    $ref: /schemas/types.yaml#/definitions/uint32-array
+    minItems: 1
+    maxItems: 31
+    uniqueItems: true
+    items:
+      maximum: 31
+    description: Physical channels that cannot be used by the DMA engine.
+
   memcpy-channels:
     $ref: /schemas/types.yaml#/definitions/uint32-array
+    minItems: 1
+    maxItems: 8
+    uniqueItems: true
+    items:
+      maximum: 63
     description: Array of u32 elements indicating which channels on the DMA
       engine are eligible for memcpy transfers