ARM: dts: exynos: Add bus nodes using VDD_MIF for Exynos4x12

This patch adds the bus nodes using VDD_MIF for Exynos4x12 SoC.
Exynos4x12 has the following AXI buses to translate data
between DRAM and DMC/ACP/C2C.

Signed-off-by: Chanwoo Choi <cw00.choi@samsung.com>
Reviewed-by: Krzysztof Kozlowski <k.kozlowski@samsung.com>
[m.reichl and linux.amoon: Tested it on exynos4412-odroidu3 board]
Tested-by: Markus Reichl <m.reichl@fivetechno.de>
Tested-by: Anand Moon <linux.amoon@gmail.com>
Signed-off-by: Krzysztof Kozlowski <k.kozlowski@samsung.com>

arch/arm/boot/dts/exynos4x12.dtsi

@@ -281,6 +281,74 @@
 		clocks = <&clock CLK_SMMU_LITE1>, <&clock CLK_FIMC_LITE1>;
 		#iommu-cells = <0>;
 	};
+
+	bus_dmc: bus_dmc {
+		compatible = "samsung,exynos-bus";
+		clocks = <&clock CLK_DIV_DMC>;
+		clock-names = "bus";
+		operating-points-v2 = <&bus_dmc_opp_table>;
+		status = "disabled";
+	};
+
+	bus_acp: bus_acp {
+		compatible = "samsung,exynos-bus";
+		clocks = <&clock CLK_DIV_ACP>;
+		clock-names = "bus";
+		operating-points-v2 = <&bus_acp_opp_table>;
+		status = "disabled";
+	};
+
+	bus_c2c: bus_c2c {
+		compatible = "samsung,exynos-bus";
+		clocks = <&clock CLK_DIV_C2C>;
+		clock-names = "bus";
+		operating-points-v2 = <&bus_dmc_opp_table>;
+		status = "disabled";
+	};
+
+	bus_dmc_opp_table: opp_table1 {
+		compatible = "operating-points-v2";
+		opp-shared;
+
+		opp@100000000 {
+			opp-hz = /bits/ 64 <100000000>;
+			opp-microvolt = <900000>;
+		};
+		opp@134000000 {
+			opp-hz = /bits/ 64 <134000000>;
+			opp-microvolt = <900000>;
+		};
+		opp@160000000 {
+			opp-hz = /bits/ 64 <160000000>;
+			opp-microvolt = <900000>;
+		};
+		opp@267000000 {
+			opp-hz = /bits/ 64 <267000000>;
+			opp-microvolt = <950000>;
+		};
+		opp@400000000 {
+			opp-hz = /bits/ 64 <400000000>;
+			opp-microvolt = <1050000>;
+		};
+	};
+
+	bus_acp_opp_table: opp_table2 {
+		compatible = "operating-points-v2";
+		opp-shared;
+
+		opp@100000000 {
+			opp-hz = /bits/ 64 <100000000>;
+		};
+		opp@134000000 {
+			opp-hz = /bits/ 64 <134000000>;
+		};
+		opp@160000000 {
+			opp-hz = /bits/ 64 <160000000>;
+		};
+		opp@267000000 {
+			opp-hz = /bits/ 64 <267000000>;
+		};
+	};
 };
 
 &combiner {