dmaengine: rcar-dmac: Document R-Car D3 bindings

R8A77995's SYS-DMAC is R-Car Gen3-compatible.
Signed-off-by: Ulrich Hecht <ulrich.hecht+renesas@gmail.com>
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Reviewed-by: Simon Horman <horms+renesas@verge.net.au>
[simon: rebased]
Signed-off-by: Simon Horman <horms+renesas@verge.net.au>
Reviewed-by: Rob Herring <robh@kernel.org>
Signed-off-by: Vinod Koul <vkoul@kernel.org>

Documentation/devicetree/bindings/dma/renesas,rcar-dmac.txt

@@ -28,6 +28,7 @@ Required Properties:
 		- "renesas,dmac-r8a7796" (R-Car M3-W)
 		- "renesas,dmac-r8a77970" (R-Car V3M)
 		- "renesas,dmac-r8a77980" (R-Car V3H)
+		- "renesas,dmac-r8a77995" (R-Car D3)
 
 - reg: base address and length of the registers block for the DMAC