clarify PicoDrive's license

- PicoDrive was originally released by fDave with simple
  "free for non-commercial use / For commercial use, separate licencing
  terms must be obtained" license and I kept it in my releases.
- in 2011, fDave re-released his code (same that I used as base
  many years ago) dual licensed with GPLv2 and MAME licenses:
    https://code.google.com/p/cyclone68000/

Based on the above I now proclaim that the whole source code is licensed
under the MAME license as more elaborate form of "for non-commercial use".
If that raises any doubt, I announce that all my modifications (which
is the vast majority of code by now) is licensed under the MAME license,
as it reads in COPYING file in this commit.

This does not affect ym2612.c/sn76496.c that were MAME licensed already
from the beginning.

platform/common/arm_utils.h

@@ -1,7 +1,3 @@
-// (c) Copyright 2006-2009 notaz, All rights reserved.
-// Free for non-commercial use.
-
-// For commercial use, separate licencing terms must be obtained.
 
 void bgr444_to_rgb32(void *to, void *from);
 void bgr444_to_rgb32_sh(void *to, void *from);

platform/common/arm_utils.s

@@ -1,10 +1,10 @@
-@ vim:filetype=armasm
-@ some color conversion and blitting routines
-
-@ (c) Copyright 2006, 2007 notaz
-@ All Rights Reserved
-
-@ vim:filetype=armasm
+/*
+ * some color conversion and blitting routines
+ * (C) notaz, 2006-2009
+ *
+ * This work is licensed under the terms of MAME license.
+ * See COPYING file in the top-level directory.
+ */
 
 .text
 .align 4
@@ -335,3 +335,4 @@ spend_cycles:
 
     bx      lr
 
+@ vim:filetype=armasm

platform/common/config.c

@@ -1,6 +1,9 @@
 /*
  * Human-readable config file management for PicoDrive
- * (c) notaz, 2008
+ * (C) notaz, 2008-2010
+ *
+ * This work is licensed under the terms of MAME license.
+ * See COPYING file in the top-level directory.
  */
 
 #include <stdio.h>

platform/common/emu.c

@@ -1,7 +1,10 @@
-// (c) Copyright 2006-2009 notaz, All rights reserved.
-// Free for non-commercial use.
-
-// For commercial use, separate licencing terms must be obtained.
+/*
+ * PicoDrive
+ * (C) notaz, 2007-2010
+ *
+ * This work is licensed under the terms of MAME license.
+ * See COPYING file in the top-level directory.
+ */
 
 #include <stdio.h>
 #include <stdlib.h>

platform/common/emu.h

@@ -1,7 +1,10 @@
-// (c) Copyright 2006-2007 notaz, All rights reserved.
-// Free for non-commercial use.
-
-// For commercial use, separate licencing terms must be obtained.
+/*
+ * PicoDrive
+ * (C) notaz, 2006-2010
+ *
+ * This work is licensed under the terms of MAME license.
+ * See COPYING file in the top-level directory.
+ */
 
 #include "port_config.h"
 

platform/common/main.c

@@ -1,7 +1,10 @@
-// (c) Copyright 2006-2009 notaz, All rights reserved.
-// Free for non-commercial use.
-
-// For commercial use, separate licencing terms must be obtained.
+/*
+ * PicoDrive
+ * (C) notaz, 2006-2010
+ *
+ * This work is licensed under the terms of MAME license.
+ * See COPYING file in the top-level directory.
+ */
 
 #include <stdio.h>
 #include <stdlib.h>

platform/common/menu_pico.c

@@ -1,3 +1,10 @@
+/*
+ * PicoDrive
+ * (C) notaz, 2010,2011
+ *
+ * This work is licensed under the terms of MAME license.
+ * See COPYING file in the top-level directory.
+ */
 #include <string.h>
 
 #include "emu.h"

platform/common/mp3.c

@@ -1,3 +1,10 @@
+/*
+ * PicoDrive
+ * (C) notaz, 2010
+ *
+ * This work is licensed under the terms of MAME license.
+ * See COPYING file in the top-level directory.
+ */
 #include "mp3.h"
 
 int mp3_find_sync_word(const unsigned char *buf, int size)

platform/common/mp3_helix.c

@@ -1,7 +1,11 @@
-// Some mp3 related code for Sega/Mega CD.
-// Uses the Helix Fixed-point MP3 decoder
-
-// (c) Copyright 2007, Grazvydas "notaz" Ignotas
+/*
+ * Some mp3 related code for Sega/Mega CD.
+ * Uses the Helix Fixed-point MP3 decoder
+ * (C) notaz, 2007-2009
+ *
+ * This work is licensed under the terms of MAME license.
+ * See COPYING file in the top-level directory.
+ */
 
 #include <stdio.h>
 #include <string.h>