power_supply: Add OF bindings documentation for tps65090-charger

This change adds the binding documentation for the tps65090-charger.

Signed-off-by: Rhyland Klein <rklein@nvidia.com>
Signed-off-by: Anton Vorontsov <anton@enomsg.org>

Documentation/devicetree/bindings/power_supply/tps65090.txt

@@ -0,0 +1,23 @@
+TPS65090 Frontend PMU with Switchmode Charger
+
+Required Properties:
+-compatible: "ti,tps65090"
+-reg: I2C slave address
+-interrupts: the interrupt output to which this device connects
+
+Optional Properties:
+-ti,enable-low-current-chrg: Enables charging when a low current is detected
+ while the default logic is to stop charging.
+
+Example:
+
+	tps65090@48 {
+		compatible = "ti,tps65090";
+		reg = <0x48>;
+		interrupts = <0 88 0x4>;
+
+		ti,enable-low-current-chrg;
+
+		regulators {
+			...
+		};