dt-bindings: display: add missing semicolon in example

Add missing semicolon in example for Sitronix ST7735R display panels.

Cc: Rob Herring <robh@kernel.org>
Cc: Noralf Trønnes <noralf@tronnes.org>
Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>
Reviewed-by: Noralf Trønnes <noralf@tronnes.org>
Signed-off-by: Rob Herring <robh@kernel.org>

Documentation/devicetree/bindings/display/sitronix,st7735r.txt

@@ -20,7 +20,7 @@ Example:
 	backlight: backlight {
 		compatible = "gpio-backlight";
 		gpios = <&gpio 44 GPIO_ACTIVE_HIGH>;
-	}
+	};
 
 	...