Input: icn8318 - use of_touchscreen helpers for inverting / swapping axes

Use the touchscreen_parse_properties() and touchscreen_report_pos() to
perform coordinates transformation, instead of DIY code, which results in a
nice cleanup.

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>