dt-bindings: dmaengine: fsl-imx: deprecate '#dma-channels' and '#dma-requests'

The generic properties, used in most of the drivers and defined in
generic dma-common DT bindings, are 'dma-channels' and 'dma-requests'.

Signed-off-by: Krzysztof Kozlowski <[e-mail]>
Reviewed-by: Rob Herring <[e-mail]>
Signed-off-by: Shawn Guo <[e-mail]>

Documentation/devicetree/bindings/dma/fsl-imx-dma.txt

···
 - #dma-cells : Has to be 1. imx-dma does not support anything else.
 
 Optional properties:
-- #dma-channels : Number of DMA channels supported. Should be 16.
-- #dma-requests : Number of DMA requests supported.
+- dma-channels : Number of DMA channels supported. Should be 16.
+- #dma-channels : deprecated
+- dma-requests : Number of DMA requests supported.
+- #dma-requests : deprecated
 
 Example:
 
···
 		reg = <0x10001000 0x1000>;
 		interrupts = <32 33>;
 		#dma-cells = <1>;
-		#dma-channels = <16>;
+		dma-channels = <16>;
 	};