arm64: dts: renesas: r8a77990: Enable DMA for SCIF2

SCIF2 on R-Car E3 can be used with both DMAC1 and DMAC2.
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Simon Horman <horms+renesas@verge.net.au>

arch/arm64/boot/dts/renesas/r8a77990.dtsi

@@ -993,7 +993,9 @@ scif2: serial@e6e88000 {
 				 <&cpg CPG_CORE R8A77990_CLK_S3D1C>,
 				 <&scif_clk>;
 			clock-names = "fck", "brg_int", "scif_clk";
-
+			dmas = <&dmac1 0x13>, <&dmac1 0x12>,
+			       <&dmac2 0x13>, <&dmac2 0x12>;
+			dma-names = "tx", "rx", "tx", "rx";
 			power-domains = <&sysc R8A77990_PD_ALWAYS_ON>;
 			resets = <&cpg 310>;
 			status = "disabled";