regulator: add documentation for regulator modes and suspend states

Add documentation for regulator modes and suspend states.

Signed-off-by: Claudiu Beznea <[e-mail]>
Signed-off-by: Mark Brown <[e-mail]>

Documentation/devicetree/bindings/regulator/act8945a-regulator.txt

···
   - inl67-supply: The input supply for REG_LDO3 and REG_LDO4
 
 Any standard regulator properties can be used to configure the single regulator.
+regulator-initial-mode, regulator-allowed-modes and regulator-mode could be
+specified using mode values from dt-bindings/regulator/active-semi,8945a-regulator.h
+file.
 
 The valid names for regulators are:
 	REG_DCDC1, REG_DCDC2, REG_DCDC3, REG_LDO1, REG_LDO2, REG_LDO3, REG_LDO4.
 
 Example:
+
+#include <dt-bindings/regulator/active-semi,8945a-regulator.h>
+
 	pmic@5b {
 		compatible = "active-semi,act8945a";
 		reg = <0x5b>;
···
 				regulator-min-microvolt = <1350000>;
 				regulator-max-microvolt = <1350000>;
 				regulator-always-on;
+
+				regulator-allowed-modes = <ACT8945A_REGULATOR_MODE_FIXED>,
+							  <ACT8945A_REGULATOR_MODE_LOWPOWER>;
+				regulator-initial-mode = <ACT8945A_REGULATOR_MODE_FIXED>;
+
+				regulator-state-mem {
+					regulator-on-in-suspend;
+					regulator-suspend-min-microvolt=<1400000>;
+					regulator-suspend-max-microvolt=<1400000>;
+					regulator-changeable-in-suspend;
+					regulator-mode=<ACT8945A_REGULATOR_MODE_LOWPOWER>;
+				};
 			};
 
 			vdd_1v2_reg: REG_DCDC2 {
···
 				regulator-min-microvolt = <1100000>;
 				regulator-max-microvolt = <1300000>;
 				regulator-always-on;
+
+				regulator-allowed-modes = <ACT8945A_REGULATOR_MODE_FIXED>,
+							  <ACT8945A_REGULATOR_MODE_LOWPOWER>;
+				regulator-initial-mode = <ACT8945A_REGULATOR_MODE_FIXED>;
+
+				regulator-state-mem {
+					regulator-off-in-suspend;
+				};
 			};
 
 			vdd_3v3_reg: REG_DCDC3 {
···
 				regulator-min-microvolt = <2500000>;
 				regulator-max-microvolt = <2500000>;
 				regulator-always-on;
+
+				regulator-allowed-modes = <ACT8945A_REGULATOR_MODE_NORMAL>,
+							  <ACT8945A_REGULATOR_MODE_LOWPOWER>;
+				regulator-initial-mode = <ACT8945A_REGULATOR_MODE_NORMAL>;
+
+				regulator-state-mem {
+					regulator-off-in-suspend;
+				};
 			};
 
 			vdd_3v3_lp_reg: REG_LDO2 {