Add touchscreen info for the Trekstor Primebook C11 convertible.

Cc: Alicia Hormann <ahormann@gmx.net>
Suggested-by: Alicia Hormann <ahormann@gmx.net>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>