dt-bindings: power: reset: Document ocelot-reset binding

Add binding documentation for the Microsemi Ocelot reset block.

Cc: devicetree@vger.kernel.org
Cc: linux-pm@vger.kernel.org
Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
Reviewed-by: Rob Herring <robh@kernel.org>
Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.co.uk>

Documentation/devicetree/bindings/power/reset/ocelot-reset.txt

+Microsemi Ocelot reset controller
+
+The DEVCPU_GCB:CHIP_REGS have a SOFT_RST register that can be used to reset the
+SoC MIPS core.
+
+Required Properties:
+ - compatible: "mscc,ocelot-chip-reset"
+
+Example:
+	reset@1070008 {
+		compatible = "mscc,ocelot-chip-reset";
+		reg = <0x1070008 0x4>;
+	};
+