dts: bindings: display: gc9x01x: Update example and documentation

Update the GC9X01X display driver binding documentation with the current
MIPI DBI SPI binding structure. The old example used direct SPI device
binding which is now deprecated in favor of the MIPI DBI API.

Signed-off-by: Benjamin Geiger <[email protected]>

Author: Benni77

dts/bindings/display/galaxycore,gc9x01x.yaml

@@ -13,17 +13,26 @@ description: |
 
   Here is an example to define a display interface:
 
-  &spi2 {
-    gc9a01a_lcd: gc9a01a_lcd@0 {
-      compatible = "galaxycore,gc9x01x";
-      reg = <0>;
-      spi-max-frequency = <100000000>;
-      cmd-data-gpios = <&gpio0 4 GPIO_ACTIVE_HIGH>;
-      reset-gpios = <&gpio0 8 GPIO_ACTIVE_LOW>;
-      pixel-format = <PANEL_PIXEL_FORMAT_RGB_565>;
-      width = <240>;
-      height = <240>;
-    };
+  / {
+      my_mipi_dbi {
+          compatible = "zephyr,mipi-dbi-spi";
+          status = "okay";
+          #address-cells = <1>;
+          #size-cells = <0>;
+          spi-dev = <&spi2>;
+          dc-gpios = <&gpio0 4 GPIO_ACTIVE_HIGH>;
+          reset-gpios = <&gpio0 8 GPIO_ACTIVE_LOW>;
+
+          gc9x01x_lcd: gc9x01x_lcd@0 {
+              compatible = "galaxycore,gc9x01x";
+              reg = <0>;
+              mipi-max-frequency = <DT_FREQ_M(100)>;
+              pixel-format = <PANEL_PIXEL_FORMAT_RGB_565>;
+              width = <240>;
+              height = <240>;
+              display-inversion;
+          };
+      };
   };