ARM: dts: exynos: Add support of bus frequency using VDD_INT for exynos3250-rinato

This patch adds the bus device-tree nodes of INT (internal) block
to enable the bus frequency scaling. The following sub-blocks share
the VDD_INT power source:
- LEFTBUS (parent device)
- RIGHTBUS
- PERIL
- LCD0
- FSYS
- MCUISP / ISP
- MFC

The LEFTBUS is parent device with devfreq ondemand governor
and the rest of devices depend on the LEFTBUS device.

Signed-off-by: Chanwoo Choi <cw00.choi@samsung.com>
Reviewed-by: Krzysztof Kozlowski <k.kozlowski@samsung.com>
Signed-off-by: Krzysztof Kozlowski <k.kozlowski@samsung.com>

arch/arm/boot/dts/exynos3250-rinato.dts

@@ -154,6 +154,47 @@
 	status = "okay";
 };
 
+&bus_leftbus {
+	devfreq-events = <&ppmu_leftbus_3>, <&ppmu_rightbus_3>;
+	vdd-supply = <&buck3_reg>;
+	status = "okay";
+};
+
+&bus_rightbus {
+	devfreq = <&bus_leftbus>;
+	status = "okay";
+};
+
+&bus_lcd0 {
+	devfreq = <&bus_leftbus>;
+	status = "okay";
+};
+
+&bus_fsys {
+	devfreq = <&bus_leftbus>;
+	status = "okay";
+};
+
+&bus_mcuisp {
+	devfreq = <&bus_leftbus>;
+	status = "okay";
+};
+
+&bus_isp {
+	devfreq = <&bus_leftbus>;
+	status = "okay";
+};
+
+&bus_peril {
+	devfreq = <&bus_leftbus>;
+	status = "okay";
+};
+
+&bus_mfc {
+	devfreq = <&bus_leftbus>;
+	status = "okay";
+};
+
 &cpu0 {
 	cpu0-supply = <&buck2_reg>;
 };