dts: bindings: kscan: Add dts entries and bindings for kscan

Indtroduction of generic device tree bindings for keyboard scan devices.
In addition, device tree node entries and dt specific bindings where
also implemented for Microchip MEC1501

Signed-off-by: Francisco Munoz <francisco.munoz.ruiz@intel.com>

dts/arm/microchip/mec1501hsz.dtsi

@@ -289,6 +289,15 @@
 			status = "disabled";
 			#io-channel-cells = <1>;
 		};
+		kscan0: kscan@40009c00 {
+			compatible = "microchip,xec-kscan";
+			reg = <0x40009c00 0x18>;
+			interrupts = <135 0>;
+			label = "KSCAN";
+			status = "disabled";
+			#address-cells = <1>;
+			#size-cells = <0>;
+		};
 	};
 };
 

dts/bindings/kscan/kscan.yaml

@@ -0,0 +1,22 @@
+# Copyright (c) 2019, Intel Corporation
+# SPDX-License-Identifier: Apache-2.0
+
+title: Keyboard Scan Matrix  Base Structure
+
+description: >
+    This binding gives the base structures for all Keyboard Matrix devices
+
+include: base.yaml
+
+child-bus: kscan
+
+properties:
+    "#address-cells":
+      required: true
+      const: 1
+    "#size-cells":
+      type: int
+      const: 0
+    label:
+      required: true
+

dts/bindings/kscan/microchip,xec-kscan.yaml

@@ -0,0 +1,19 @@
+# Copyright (c) 2019, Intel Corporation
+# SPDX-License-Identifier: Apache-2.0
+
+title: Microchip XEC Keyboard Scan Matrix
+
+description: >
+    This is a representation of the Microchip XEC Keyboard Matrix controller
+
+compatible: "microchip,xec-kscan"
+
+include: kscan.yaml
+
+properties:
+    reg:
+      required: true
+
+    interrupts:
+      required: true
+...