dt-bindings: dmaengine: sprd: deprecate '#dma-channels'

The generic property, used in most of the drivers and defined in generic
dma-common DT bindings, is 'dma-channels'.

Signed-off-by: Krzysztof Kozlowski <[e-mail]>
Reviewed-by: Rob Herring <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]
Signed-off-by: Vinod Koul <[e-mail]>

Documentation/devicetree/bindings/dma/sprd-dma.txt

···
 - interrupts: Should contain one interrupt shared by all channel.
 - #dma-cells: must be <1>. Used to represent the number of integer
 	cells in the dmas property of client device.
-- #dma-channels : Number of DMA channels supported. Should be 32.
+- dma-channels : Number of DMA channels supported. Should be 32.
 - clock-names: Should contain the clock of the DMA controller.
 - clocks: Should contain a clock specifier for each entry in clock-names.
+
+Deprecated properties:
+- #dma-channels : Number of DMA channels supported. Should be 32.
 
 Example:
 
···
 	reg = <0x20100000 0x4000>;
 	interrupts = <GIC_SPI 50 IRQ_TYPE_LEVEL_HIGH>;
 	#dma-cells = <1>;
-	#dma-channels = <32>;
+	dma-channels = <32>;
 	clock-names = "enable";
 	clocks = <&clk_ap_ahb_gates 5>;
 };