dt-bindings/goldfish-pic: Add device tree binding for Goldfish PIC driver

Add documentation for DT binding of Goldfish PIC driver. The compatible
string used by OS for binding the driver is "google,goldfish-pic".
Acked-by: NRob Herring <robh@kernel.org>
Signed-off-by: NMiodrag Dinic <miodrag.dinic@mips.com>
Signed-off-by: NGoran Ferenc <goran.ferenc@mips.com>
Signed-off-by: NAleksandar Markovic <aleksandar.markovic@mips.com>
Signed-off-by: NMarc Zyngier <marc.zyngier@arm.com>

Documentation/devicetree/bindings/interrupt-controller/google,goldfish-pic.txt

+Android Goldfish PIC
+
+Android Goldfish programmable interrupt device used by Android
+emulator.
+
+Required properties:
+
+- compatible : should contain "google,goldfish-pic"
+- reg        : <registers mapping>
+- interrupts : <interrupt mapping>
+
+Example for mips when used in cascade mode:
+
+        cpuintc {
+                #interrupt-cells = <0x1>;
+                #address-cells = <0>;
+                interrupt-controller;
+                compatible = "mti,cpu-interrupt-controller";
+        };
+
+        interrupt-controller@1f000000 {
+                compatible = "google,goldfish-pic";
+                reg = <0x1f000000 0x1000>;
+
+                interrupt-controller;
+                #interrupt-cells = <0x1>;
+
+                interrupt-parent = <&cpuintc>;
+                interrupts = <0x2>;
+        };

MAINTAINERS

@@ -867,6 +867,11 @@ S:	Supported
 F:	drivers/android/
 F:	drivers/staging/android/
 
+ANDROID GOLDFISH PIC DRIVER
+M:	Miodrag Dinic <miodrag.dinic@mips.com>
+S:	Supported
+F:	Documentation/devicetree/bindings/interrupt-controller/google,goldfish-pic.txt
+
 ANDROID GOLDFISH RTC DRIVER
 M:	Miodrag Dinic <miodrag.dinic@mips.com>
 S:	Supported