dt-bindings: Add devicetree bindings

Add snapshot of device tree bindings from keystone common kernel, branch
"android-mainline-keystone-qcom-release" at c4c12103f9c0 ("Snap for 9228065
from e32903b9a63bb558df8b803b076619c53c16baad to
android-mainline-keystone-qcom-release").

Change-Id: I7682079615cbd9f29340a5c1f2a1d84ec441a1f1
Signed-off-by: Melody Olvera <quic_molvera@quicinc.com>

bindings/interrupt-controller/csky,apb-intc.txt

@@ -0,0 +1,62 @@
+==============================
+C-SKY APB Interrupt Controller
+==============================
+
+C-SKY APB Interrupt Controller is a simple soc interrupt controller
+on the apb bus and we only use it as root irq controller.
+
+ - csky,apb-intc is used in a lot of csky fpgas and socs, it support 64 irq nums.
+ - csky,dual-apb-intc consists of 2 apb-intc and 128 irq nums supported.
+ - csky,gx6605s-intc is gx6605s soc internal irq interrupt controller, 64 irq nums.
+
+=============================
+intc node bindings definition
+=============================
+
+	Description: Describes APB interrupt controller
+
+	PROPERTIES
+
+	- compatible
+		Usage: required
+		Value type: <string>
+		Definition: must be "csky,apb-intc"
+				    "csky,dual-apb-intc"
+				    "csky,gx6605s-intc"
+	- #interrupt-cells
+		Usage: required
+		Value type: <u32>
+		Definition: must be <1>
+	- reg
+		Usage: required
+		Value type: <u32 u32>
+		Definition: <phyaddr size> in soc from cpu view
+	- interrupt-controller:
+		Usage: required
+	- csky,support-pulse-signal:
+		Usage: select
+		Description: to support pulse signal flag
+
+Examples:
+---------
+
+	intc: interrupt-controller@500000 {
+		compatible = "csky,apb-intc";
+		#interrupt-cells = <1>;
+		reg = <0x00500000 0x400>;
+		interrupt-controller;
+	};
+
+	intc: interrupt-controller@500000 {
+		compatible = "csky,dual-apb-intc";
+		#interrupt-cells = <1>;
+		reg = <0x00500000 0x400>;
+		interrupt-controller;
+	};
+
+	intc: interrupt-controller@500000 {
+		compatible = "csky,gx6605s-intc";
+		#interrupt-cells = <1>;
+		reg = <0x00500000 0x400>;
+		interrupt-controller;
+	};