dt-bindings: dma: Increase iommu maxItems for BAM DMA

Since SM8250 BAM DMA engine supports six iommu entries,
increase the maxItems in the iommu property section, without
which 'dtbs_check' would throw errors.

Acked-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Tested-by: Anders Roxell <anders.roxell@linaro.org>
Tested-by: Linux Kernel Functional Testing <lkft@linaro.org>
Signed-off-by: Bhupesh Sharma <bhupesh.sharma@linaro.org>
Link: https://lore.kernel.org/r/20230630082230.2264698-3-bhupesh.sharma@linaro.org
Signed-off-by: Vinod Koul <vkoul@kernel.org>

Documentation/devicetree/bindings/dma/qcom,bam-dma.yaml

@@ -44,7 +44,7 @@ properties:
 
   iommus:
     minItems: 1
-    maxItems: 4
+    maxItems: 6
 
   num-channels:
     $ref: /schemas/types.yaml#/definitions/uint32