dts: bindings: add "zephyr,displays" compatible

Add "zephyr,displays" compatible for passing available display
controllers nodes to graphical libraries that have multi-display support
like LVGL

Signed-off-by: Abderrahmane JARMOUNI <[email protected]>

Author: JarmouniA

dts/bindings/display/zephyr,displays.yaml

@@ -0,0 +1,15 @@
+# Copyright (c) 2025 Abderrahmane JARMOUNI
+# SPDX-License-Identifier: Apache-2.0
+
+description: |
+  Display controllers to pass to graphical libraries like LVGL.
+  Only one node with this compatible is allowed in the DeviceTree
+
+compatible: "zephyr,displays"
+
+properties:
+  displays:
+    type: phandles
+    required: true
+    description: |
+      Nodes of display controllers for graphical libraries to use