Add a compatible string for the Himax HX83100A touch controller.

The HX83100A presents touch events on the internal bus rather than
offering a dedicated event register like the other chips in this family
do.
Signed-off-by: Felix Kaechele <felix@kaechele.ca>
Acked-by: Conor Dooley <conor.dooley@microchip.com>
Link: https://lore.kernel.org/r/20240620145019.156187-2-felix@kaechele.caSigned-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>