dt-bindings: display/panel: Add Leadtek ltk035c5444t

Add binding for the leadtek ltk035c5444t, which is a 640x480
mipi-dbi over spi / 24-bit RGB panel based on the newvision
NV03052C chipset.

It is found in the Anbernic RG350M mips handheld.
Signed-off-by: Christophe Branchereau <cbranchereau@gmail.com>
Signed-off-by: Paul Cercueil <paul@crapouillou.net>
Reviewed-by: Rob Herring <robh@kernel.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20220311170240.173846-5-cbranchereau@gmail.com

Documentation/devicetree/bindings/display/panel/leadtek,ltk035c5444t.yaml

+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/display/panel/leadtek,ltk035c5444t.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Leadtek ltk035c5444t 3.5" (640x480 pixels) 24-bit IPS LCD panel
+
+maintainers:
+  - Paul Cercueil <paul@crapouillou.net>
+  - Christophe Branchereau <cbranchereau@gmail.com>
+
+allOf:
+  - $ref: panel-common.yaml#
+  - $ref: /schemas/spi/spi-peripheral-props.yaml#
+
+properties:
+  compatible:
+    const: leadtek,ltk035c5444t
+
+  backlight: true
+  port: true
+  power-supply: true
+  reg: true
+  reset-gpios: true
+
+required:
+  - compatible
+  - power-supply
+  - reset-gpios
+
+unevaluatedProperties: false
+
+examples:
+  - |
+    #include <dt-bindings/gpio/gpio.h>
+
+    spi {
+        #address-cells = <1>;
+        #size-cells = <0>;
+        panel@0 {
+            compatible = "leadtek,ltk035c5444t";
+            reg = <0>;
+
+            spi-3wire;
+            spi-max-frequency = <3125000>;
+
+            reset-gpios = <&gpe 2 GPIO_ACTIVE_LOW>;
+
+            backlight = <&backlight>;
+            power-supply = <&vcc>;
+
+            port {
+                panel_input: endpoint {
+                    remote-endpoint = <&panel_output>;
+                };
+            };
+        };
+    };