dmaengine: usb-dmac: add binding for r8a77965

This patch adds binding for r8a77965 (R-Car M3-N).

Signed-off-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>

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

@@ -11,6 +11,7 @@ Required Properties:
 	  - "renesas,r8a7794-usb-dmac" (R-Car E2)
 	  - "renesas,r8a7795-usb-dmac" (R-Car H3)
 	  - "renesas,r8a7796-usb-dmac" (R-Car M3-W)
+	  - "renesas,r8a77965-usb-dmac" (R-Car M3-N)
 - reg: base address and length of the registers block for the DMAC
 - interrupts: interrupt specifiers for the DMAC, one for each entry in
   interrupt-names.