platform/chrome: chromeos_laptop - use device properties for Pixel

Now that Atmel driver uses generic device properties we can use them
instead of platform data when setting up touchpad on the original
Google Pixel.

Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Signed-off-by: Benson Leung <bleung@chromium.org>