platform/x86: touchscreen_dmi: Handle device properties with software node API

The old device property API (device_add_properties()) is
going to be removed. Replacing the it with the software node
API equivalent, device_create_managed_software_node().

Signed-off-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Link: https://lore.kernel.org/r/20210304082023.17689-1-heikki.krogerus@linux.intel.com
Signed-off-by: Hans de Goede <hdegoede@redhat.com>