This patch adds the TSC-40 serial touchscreen driver and should be
compatible with TSC-10 and TSC-25.

The driver was written by Linutronix on behalf of Bachmann electronic GmbH.
Signed-off-by: NSebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: NChristian Gmeiner <christian.gmeiner@gmail.com>
Signed-off-by: NDmitry Torokhov <dtor@mail.ru>