dt-bindings: dmaengine: Add dma-channel-mask to Tegra GPCDMA

Add dma-channel-mask property in Tegra GPCDMA document.

The property would help to specify the channels to be used in
kernel and reserve few for the firmware. This was previously
achieved by limiting the channel number to 31 in the driver.
This is wrong and does not align with the hardware. Correct
this and set the max interrupts to 32.

Signed-off-by: Akhil R <akhilrajeev@nvidia.com>
Acked-by: Thierry Reding <treding@nvidia.com>
Acked-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Link: https://lore.kernel.org/r/20221110171748.40304-2-akhilrajeev@nvidia.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>

Author: akhilr-nv

Documentation/devicetree/bindings/dma/nvidia,tegra186-gpc-dma.yaml

@@ -39,7 +39,7 @@ properties:
       Should contain all of the per-channel DMA interrupts in
       ascending order with respect to the DMA channel index.
     minItems: 1
-    maxItems: 31
+    maxItems: 32
 
   resets:
     maxItems: 1
@@ -52,6 +52,9 @@ properties:
 
   dma-coherent: true
 
+  dma-channel-mask:
+    maxItems: 1
+
 required:
   - compatible
   - reg
@@ -60,6 +63,7 @@ required:
   - reset-names
   - "#dma-cells"
   - iommus
+  - dma-channel-mask
 
 additionalProperties: false
 
@@ -108,5 +112,6 @@ examples:
         #dma-cells = <1>;
         iommus = <&smmu TEGRA186_SID_GPCDMA_0>;
         dma-coherent;
+        dma-channel-mask = <0xfffffffe>;
     };
 ...