next-cube: add my copyright to the top of the file

This series has involved rewriting and/or updating a considerable part of the
next-cube emulation so update the copyright in next-cube.c to reflect this.

Signed-off-by: Mark Cave-Ayland <mark.cave-ayland@ilande.co.uk>
Reviewed-by: Thomas Huth <huth@tuxfamily.org>
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Message-ID: <20241222130012.1013374-34-mark.cave-ayland@ilande.co.uk>
Signed-off-by: Thomas Huth <huth@tuxfamily.org>

hw/m68k/next-cube.c

@@ -2,6 +2,7 @@
  * NeXT Cube System Driver
  *
  * Copyright (c) 2011 Bryce Lanham
+ * Copyright (c) 2024 Mark Cave-Ayland
  *
  * This code is free software; you can redistribute it and/or modify
  * it under the terms of the GNU General Public License as published