riscv: sifive: dts: fu540: add U-Boot dmc node

Add dmc node to enable ddr driver. dmc is used to
initialize the memory controller.

Signed-off-by: Pragnesh Patel <pragnesh.patel@sifive.com>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
Tested-by: Bin Meng <bmeng.cn@gmail.com>
Reviewed-by: Jagan Teki <jagan@amarulasolutions.com>
Tested-by: Jagan Teki <jagan@amarulasolutions.com>
diff --git a/arch/riscv/dts/fu540-c000-u-boot.dtsi b/arch/riscv/dts/fu540-c000-u-boot.dtsi
index fbfe296..fc91a7c 100644
--- a/arch/riscv/dts/fu540-c000-u-boot.dtsi
+++ b/arch/riscv/dts/fu540-c000-u-boot.dtsi
@@ -59,6 +59,15 @@
 			reg = <0x0 0x2000000 0x0 0xc0000>;
 			u-boot,dm-spl;
 		};
+		dmc: dmc@100b0000 {
+			compatible = "sifive,fu540-c000-ddr";
+			reg = <0x0 0x100b0000 0x0 0x0800
+			       0x0 0x100b2000 0x0 0x2000
+			       0x0 0x100b8000 0x0 0x0fff>;
+			clocks = <&prci PRCI_CLK_DDRPLL>;
+			clock-frequency = <933333324>;
+			u-boot,dm-spl;
+		};
 	};
 };