samples: lvgl: multi_display: add SDL Window titles

Add custom titles to SDL windows in native sim

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

Author: JarmouniA

samples/modules/lvgl/multi_display/boards/native_sim_64.overlay

@@ -12,6 +12,7 @@
 	};
 
 	sdl_dc {
+		title = "Zephyr Display 1";
 		width = <800>;
 		height = <600>;
 		status = "okay";
@@ -31,6 +32,7 @@
 
 	sdl_dc2: sdl-dc2 {
 		compatible = "zephyr,sdl-dc";
+		title = "Zephyr Display 2";
 		width = <800>;
 		height = <600>;
 		status = "okay";