TTY: Maintainer change

Clearly, I am a glutton for punishment.  I'll see if I can see Alan's
changes through to the end, otherwise I'll be fending off a lot of bug
reports for usb-serial devices.

Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>