ARM: S3C24XX: touchscreen device definition

Add definition for the touchscreen driver platform data and initial
support for the H1940 machine.

Signed-off-by: Arnaud Patard <arnaud.patard@rtp-net.org>
Signed-off-by: Ben Dooks <ben@simtec.co.uk>
Signed-off-by: Ben Dooks <ben-linux@fluff.org>