Input: cyttsp - switch to using device properties

Drop support for platform data passed via a C-structure and switch to
device properties instead, which should make the driver compatible
with all platforms: OF, ACPI and static boards. Static boards should
use property sets to communicate device parameters to the driver.

Signed-off-by: Oreste Salerno <oreste.salerno@tomtom.com>
Acked-by: Rob Herring <robh@kernel.org>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>