dts: Add bindings for the imx lcd display controller

Adds device tree bindings for the imx enhanced LCD interface (eLCDIF)
controller. The compatible is reused from linux.

Signed-off-by: Maureen Helm <maureen.helm@nxp.com>

dts/arm/nxp/nxp_rt.dtsi

@@ -180,6 +180,14 @@
 			label = "PINMUX_0";
 		};
 
+		lcdif1: display-controller@402b8000 {
+			compatible = "fsl,imx6sx-lcdif";
+			reg = <0x402b8000 0x4000>;
+			interrupts = <42 0>;
+			label = "ELCDIF_1";
+			status = "disabled";
+		};
+
 		spi1: spi@40394000 {
 			compatible = "nxp,imx-lpspi";
 			reg = <0x40394000 0x4000>;

dts/bindings/display/fsl,imx6sx-lcdif.yaml

@@ -0,0 +1,37 @@
+#
+# Copyright (c) 2019, NXP
+#
+# SPDX-License-Identifier: Apache-2.0
+#
+---
+title: NXP Enhanced LCD Interface (eLCDIF) controller
+version: 0.1
+
+description: >
+    This binding gives a base representation of the NXP i.MX eLCDIF controller
+
+properties:
+    compatible:
+      type: string
+      category: required
+      description: compatible strings
+      constraint: "fsl,imx6sx-lcdif"
+
+    reg:
+      type: array
+      description: mmio register space
+      generation: define
+      category: required
+
+    interrupts:
+      type: array
+      category: required
+      description: required interrupts
+      generation: define
+
+    label:
+      type: string
+      category: required
+      description: Human readable string describing the device (used by Zephyr for API name)
+      generation: define
+...