regulator: twl: adapt twl-regulator driver to dt

Modify the twl regulator driver to extract the regulator_init_data from
device tree when passed, instead of getting it through platform_data
structures (on non-DT builds)

Also add documentation for TWL regulator specific bindings.
Signed-off-by: Rajendra Nayak <rnayak@ti.com>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>

Documentation/devicetree/bindings/regulator/twl-regulator.txt

+TWL family of regulators
+
+Required properties:
+For twl6030 regulators/LDOs
+- compatible:
+  - "ti,twl6030-vaux1" for VAUX1 LDO
+  - "ti,twl6030-vaux2" for VAUX2 LDO
+  - "ti,twl6030-vaux3" for VAUX3 LDO
+  - "ti,twl6030-vmmc" for VMMC LDO
+  - "ti,twl6030-vpp" for VPP LDO
+  - "ti,twl6030-vusim" for VUSIM LDO
+  - "ti,twl6030-vana" for VANA LDO
+  - "ti,twl6030-vcxio" for VCXIO LDO
+  - "ti,twl6030-vdac" for VDAC LDO
+  - "ti,twl6030-vusb" for VUSB LDO
+  - "ti,twl6030-clk32kg" for CLK32KG RESOURCE
+  - "ti,twl6030-vdd1" for VDD1 SMPS
+  - "ti,twl6030-vdd2" for VDD2 SMPS
+  - "ti,twl6030-vdd3" for VDD3 SMPS
+For twl6025 regulators/LDOs
+- compatible:
+  - "ti,twl6025-ldo1" for LDO1 LDO
+  - "ti,twl6025-ldo2" for LDO2 LDO
+  - "ti,twl6025-ldo3" for LDO3 LDO
+  - "ti,twl6025-ldo4" for LDO4 LDO
+  - "ti,twl6025-ldo5" for LDO5 LDO
+  - "ti,twl6025-ldo6" for LDO6 LDO
+  - "ti,twl6025-ldo7" for LDO7 LDO
+  - "ti,twl6025-ldoln" for LDOLN LDO
+  - "ti,twl6025-ldousb" for LDOUSB LDO
+  - "ti,twl6025-smps3" for SMPS3 SMPS
+  - "ti,twl6025-smps4" for SMPS4 SMPS
+  - "ti,twl6025-vio" for VIO SMPS
+For twl4030 regulators/LDOs
+- compatible:
+  - "ti,twl4030-vaux1" for VAUX1 LDO
+  - "ti,twl4030-vaux2" for VAUX2 LDO
+  - "ti,twl5030-vaux2" for VAUX2 LDO
+  - "ti,twl4030-vaux3" for VAUX3 LDO
+  - "ti,twl4030-vaux4" for VAUX4 LDO
+  - "ti,twl4030-vmmc1" for VMMC1 LDO
+  - "ti,twl4030-vmmc2" for VMMC2 LDO
+  - "ti,twl4030-vpll1" for VPLL1 LDO
+  - "ti,twl4030-vpll2" for VPLL2 LDO
+  - "ti,twl4030-vsim" for VSIM LDO
+  - "ti,twl4030-vdac" for VDAC LDO
+  - "ti,twl4030-vintana2" for VINTANA2 LDO
+  - "ti,twl4030-vio" for VIO LDO
+  - "ti,twl4030-vdd1" for VDD1 SMPS
+  - "ti,twl4030-vdd2" for VDD2 SMPS
+  - "ti,twl4030-vintana1" for VINTANA1 LDO
+  - "ti,twl4030-vintdig" for VINTDIG LDO
+  - "ti,twl4030-vusb1v5" for VUSB1V5 LDO
+  - "ti,twl4030-vusb1v8" for VUSB1V8 LDO
+  - "ti,twl4030-vusb3v1" for VUSB3V1 LDO
+
+Optional properties:
+- Any optional property defined in bindings/regulator/regulator.txt
+
+Example:
+
+	xyz: regulator@0 {
+		compatible = "ti,twl6030-vaux1";
+		regulator-min-microvolt  = <1000000>;
+		regulator-max-microvolt  = <3000000>;
+	};