dt-bindings: input: touchscreen: himax,hx83112b: add HX83100A

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 <[e-mail]>
Acked-by: Conor Dooley <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]
Signed-off-by: Dmitry Torokhov <[e-mail]>

Documentation/devicetree/bindings/input/touchscreen/himax,hx83112b.yaml

···
 properties:
   compatible:
     enum:
+      - himax,hx83100a
       - himax,hx83112b
 
   reg: