ARM: shmobile: r8a7791: Reference DMA channels in MMCIF DT node

Add references to the transmit and receive DMA channels in the MMCIF
node.

Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
Acked-by: Geert Uytterhoeven <geert+renesas@glider.be>
Tested-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Signed-off-by: Simon Horman <horms+renesas@verge.net.au>

arch/arm/boot/dts/r8a7791.dtsi

@@ -405,6 +405,8 @@
 		reg = <0 0xee200000 0 0x80>;
 		interrupts = <0 169 IRQ_TYPE_LEVEL_HIGH>;
 		clocks = <&mstp3_clks R8A7791_CLK_MMCIF0>;
+		dmas = <&dmac0 0xd1>, <&dmac0 0xd2>;
+		dma-names = "tx", "rx";
 		reg-io-width = <4>;
 		status = "disabled";
 	};