Staging: HTC Dream: touchscreen driver for staging

This adds support for synaptic touchscreen, used in HTC dream
cellphone.

This is original version from Arve, fixed only to compile; I do have
cleaner version, but I broken something inside, and this will preserve
authorship better. I originally tried to push the driver directly to
input/touchscreen, but the driver has some issues with interrupt
handling that are more difficult to fix than I expected at first.

Signed-off-by: Arve Hjønnevåg <arve@android.com>
Signed-off-by: Pavel Machek <pavel@ucw.cz>