MIPS: mscc: ocelot: add interrupt controller properties to GPIO controller

The GPIO controller also serves as an interrupt controller for events
on the GPIO it handles.

An interrupt occurs whenever a GPIO line has changed.
Signed-off-by: Quentin Schulz <quentin.schulz@bootlin.com>
Acked-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Paul Burton <paul.burton@mips.com>
Patchwork: https://patchwork.linux-mips.org/patch/20015/
Cc: robh+dt@kernel.org
Cc: mark.rutland@arm.com
Cc: ralf@linux-mips.org
Cc: jhogan@kernel.org
Cc: linux-gpio@vger.kernel.org
Cc: linux-mips@linux-mips.org
Cc: devicetree@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Cc: thomas.petazzoni@bootlin.com

arch/mips/boot/dts/mscc/ocelot.dtsi

@@ -168,6 +168,9 @@ gpio: pinctrl@1070034 {
 			gpio-controller;
 			#gpio-cells = <2>;
 			gpio-ranges = <&gpio 0 0 22>;
+			interrupt-controller;
+			interrupts = <13>;
+			#interrupt-cells = <2>;
 
 			uart_pins: uart-pins {
 				pins = "GPIO_6", "GPIO_7";