dt-bindings: misc: ASPEED coprocessor interrupt controller

Add the device-tree binding definition for the AST2400
and AST2500 coprocessor interrupt controller
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Rob Herring <robh@kernel.org>

Documentation/devicetree/bindings/misc/aspeed,cvic.txt

+* ASPEED AST2400 and AST2500 coprocessor interrupt controller
+
+This file describes the bindings for the interrupt controller present
+in the AST2400 and AST2500 BMC SoCs which provides interrupt to the
+ColdFire coprocessor.
+
+It is not a normal interrupt controller and it would be rather
+inconvenient to create an interrupt tree for it as it somewhat shares
+some of the same sources as the main ARM interrupt controller but with
+different numbers.
+
+The AST2500 supports a SW generated interrupt
+
+Required properties:
+- reg: address and length of the register for the device.
+- compatible: "aspeed,cvic" and one of:
+		"aspeed,ast2400-cvic"
+	      or
+		"aspeed,ast2500-cvic"
+
+- valid-sources: One cell, bitmap of supported sources for the implementation
+
+Optional properties;
+- copro-sw-interrupts: List of interrupt numbers that can be used as
+		       SW interrupts from the ARM to the coprocessor.
+		       (AST2500 only)
+
+Example:
+
+	cvic: copro-interrupt-controller@1e6c2000 {
+		compatible = "aspeed,ast2500-cvic";
+		valid-sources = <0xffffffff>;
+		copro-sw-interrupts = <1>;
+		reg = <0x1e6c2000 0x80>;
+	};