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/openrisc,ompic.txt

@@ -0,0 +1,22 @@
+Open Multi-Processor Interrupt Controller
+
+Required properties:
+
+- compatible : This should be "openrisc,ompic"
+- reg : Specifies base physical address and size of the register space. The
+  size is based on the number of cores the controller has been configured
+  to handle, this should be set to 8 bytes per cpu core.
+- interrupt-controller : Identifies the node as an interrupt controller.
+- #interrupt-cells : This should be set to 0 as this will not be an irq
+  parent.
+- interrupts : Specifies the interrupt line to which the ompic is wired.
+
+Example:
+
+ompic: interrupt-controller@98000000 {
+	compatible = "openrisc,ompic";
+	reg = <0x98000000 16>;
+	interrupt-controller;
+	#interrupt-cells = <0>;
+	interrupts = <1>;
+};