feat(examples/ffmpeg_player): specify default decoder (lvgl#9218)

Co-authored-by: Copilot <175728472+Copilot@users.noreply.github.com>

Author: cnjhb

examples/libs/ffmpeg/lv_example_ffmpeg_2.c

@@ -18,6 +18,9 @@ void lv_example_ffmpeg_2(void)
     /*It will use the LVGL filesystem abstraction (not the OS filesystem)
      *if `LV_FFMPEG_PLAYER_USE_LV_FS` is set.*/
     lv_obj_t * player = lv_ffmpeg_player_create(lv_screen_active());
+    /*Note: "h264_v4l2m2m" is a Linux-specific hardware decoder example, available only on Linux systems with V4L2 support.
+     *In the absence of support, it will fall back to software decoding.*/
+    lv_ffmpeg_player_set_decoder(player, "h264_v4l2m2m");
     lv_ffmpeg_player_set_src(player, PATH_PREFIX "lvgl/examples/libs/ffmpeg/birds.mp4");
     lv_ffmpeg_player_set_auto_restart(player, true);
     lv_ffmpeg_player_set_cmd(player, LV_FFMPEG_PLAYER_CMD_START);