Input: driver for touchscreen on iPaq h3xxx

This adds a driver for the touchscreen connected to the Atmel
microcontroller on the iPAQ h3xxx series.

Based on a driver from handhelds.org 2.6.21 kernel, written by Alessandro
GARDICH, with the bulk of the code for the new input architecture rewritten
by Dmitry Atamonow, and the final polish by Linus Walleij.

Signed-off-by: Alessandro GARDICH <gremlin@gremlin.it>
Signed-off-by: Dmitry Artamonow <mad_soft@inbox.ru>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>