dt-bindings: touchscreen: Convert EETI EXC3000 touchscreen to json-schema

Convert the EETI EXC3000 binding to DT schema format using json-schema

Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.com>
Reviewed-by: Rob Herring <robh@kernel.org>
Link: https://lore.kernel.org/r/20200805160520.456570-2-sebastian.reichel@collabora.com


Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>