serial/8250_pnp: add a new Fujitsu Wacom Tablet PC device

This is a new two finger touch Fujitsu Wacom Tablet PC.

Signed-off-by: Ping Cheng <pingc@wacom.com>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Cc: Dmitry Torokhov <dtor@mail.ru>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>