V4L/DVB (9619): tvaudio: update initial comments

A driver used on several bttv boards since 2000 is not experimental
anymore ;) Remove it from the comments.

While there, update copyrights addind a quick note about the "recent"
updates since 2005.
Signed-off-by: NMauro Carvalho Chehab <mchehab@redhat.com>

drivers/media/video/tvaudio.c

 /*
- * experimental driver for simple i2c audio chips.
+ * Driver for simple i2c audio chips.
  *
  * Copyright (c) 2000 Gerd Knorr
  * based on code by:
@@ -7,6 +7,10 @@
  *   Steve VanDeBogart (vandebo@uclink.berkeley.edu)
  *   Greg Alexander (galexand@acm.org)
  *
+ * Copyright(c) 2005-2008 Mauro Carvalho Chehab
+ *	- Some cleanups, code fixes, etc
+ *	- Convert it to V4L2 API
+ *
  * This code is placed under the terms of the GNU General Public License
  *
  * OPTIONS: