dt-bindings: display: Add SSD133x OLED controllers

Add a Device Tree binding schema for the OLED panels based on the
Solomon SSD133x family of controllers.

Signed-off-by: Javier Martinez Canillas <javierm@redhat.com>
Reviewed-by: Rob Herring <robh@kernel.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20231229112026.2797483-4-javierm@redhat.com

Documentation/devicetree/bindings/display/solomon,ssd133x.yaml

+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/display/solomon,ssd133x.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Solomon SSD133x OLED Display Controllers
+
+maintainers:
+  - Javier Martinez Canillas <javierm@redhat.com>
+
+allOf:
+  - $ref: solomon,ssd-common.yaml#
+
+properties:
+  compatible:
+    enum:
+      - solomon,ssd1331
+
+  solomon,width:
+    default: 96
+
+  solomon,height:
+    default: 64
+
+required:
+  - compatible
+  - reg
+
+unevaluatedProperties: false
+
+examples:
+  - |
+    spi {
+        #address-cells = <1>;
+        #size-cells = <0>;
+
+        oled@0 {
+            compatible = "solomon,ssd1331";
+            reg = <0x0>;
+            reset-gpios = <&gpio2 7>;
+            dc-gpios = <&gpio2 8>;
+            spi-max-frequency = <10000000>;
+        };
+    };