ARM: dts: AM33XX: Add device tree OPP table

Add DT OPP table for AM33XX family of devices. This data is
decoded by OF with of_init_opp_table() helper function.

Also adds cpu0 supply name to the corresponding dts files.
cpu0-supply name is used by cpufreq-cpu0 driver to get the
regulator pointer for voltage modifications.

Signed-off-by: AnilKumar Ch <anilkumar@ti.com>
Signed-off-by: Benoit Cousson <b-cousson@ti.com>

arch/arm/boot/dts/am335x-bone.dts

@@ -13,6 +13,12 @@
 	model = "TI AM335x BeagleBone";
 	compatible = "ti,am335x-bone", "ti,am33xx";
 
+	cpus {
+		cpu@0 {
+			cpu0-supply = <&dcdc2_reg>;
+		};
+	};
+
 	memory {
 		device_type = "memory";
 		reg = <0x80000000 0x10000000>; /* 256 MB */

arch/arm/boot/dts/am335x-evm.dts

@@ -13,6 +13,12 @@
 	model = "TI AM335x EVM";
 	compatible = "ti,am335x-evm", "ti,am33xx";
 
+	cpus {
+		cpu@0 {
+			cpu0-supply = <&vdd1_reg>;
+		};
+	};
+
 	memory {
 		device_type = "memory";
 		reg = <0x80000000 0x10000000>; /* 256 MB */

arch/arm/boot/dts/am33xx.dtsi

@@ -25,6 +25,21 @@
 	cpus {
 		cpu@0 {
 			compatible = "arm,cortex-a8";
+
+			/*
+			 * To consider voltage drop between PMIC and SoC,
+			 * tolerance value is reduced to 2% from 4% and
+			 * voltage value is increased as a precaution.
+			 */
+			operating-points = <
+				/* kHz    uV */
+				720000  1285000
+				600000  1225000
+				500000  1125000
+				275000  1125000
+			>;
+			voltage-tolerance = <2>; /* 2 percentage */
+			clock-latency = <300000>; /* From omap-cpufreq driver */
 		};
 	};