char/mwave: drop it

char/mwave: drop it

When I tried to clean up the driver a bit, Arnd noted:
> According to thinkwiki.de, the 3780i modem was only used in a
> couple of Thinkpad models that are now over 25 years old, using
> Pentium II processors, and they all have a physical RS232 port
> that can be used to connect an external modem instead.
>
> Maybe we can just retire this driver?

So instead of the clean up, drop the driver altogether.

Signed-off-by: Jiri Slaby (SUSE) <jirislaby@kernel.org>
Suggested-by: Arnd Bergmann <arnd@arndb.de>
Link: https://lore.kernel.org/all/b8834e5d-fdde-4b1a-8757-288dddc507a9@app.fastmail.com/
Link: https://patch.msgid.link/20251124103952.995229-1-jirislaby@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>