dts: bindings: add yaml file for Kinetis USBD support

Add yaml file for Kinetis USBD support.

Signed-off-by: Johann Fischer <j.fischer@phytec.de>

dts/bindings/usb/nxp,kinetis-usbd.yaml

@@ -0,0 +1,38 @@
+#
+# Copyright (c) 2018 PHYTEC Messtechnik GmbH
+#
+# SPDX-License-Identifier: Apache-2.0
+#
+---
+title: NXP Kinetis USBD
+id: nxp,kinetis-usbd
+version: 0.1
+
+description: >
+    NPX Kinetis USBFSOTG Controller in device mode
+
+inherits:
+    !include usb-ep.yaml
+
+properties:
+    compatible:
+      constraint: "nxp,kinetis-usbd"
+
+    reg:
+      type: array
+      description: mmio register space
+      generation: define
+      category: required
+
+    interrupts:
+      type: array
+      category: required
+      description: required interrupts
+      generation: define
+
+    interrupt-names:
+      type: stringlist
+      category: optional
+      description: readable string describing the interrupts
+      generation: define
+...