dt-bindings: input: touchscreen: edt-ft5x06: change reg property

A test with the command below gives this error:

arch/arm/boot/dts/rk3188-bqedison2qc.dt.yaml:
touchscreen@3e: reg:0:0: 56 was expected

The touchscreen chip on 'rk3188-bqedison2qc' and other BQ models
was shipped with different addresses then the binding currently allows.
Change the reg property that any address will pass.

make ARCH=arm dtbs_check
DT_SCHEMA_FILES=Documentation/devicetree/bindings/input/touchscreen/
edt-ft5x06.yaml

Signed-off-by: Johan Jonker <jbx6244@gmail.com>
Acked-by: Heiko Stuebner <heiko@sntech.de>
Signed-off-by: Rob Herring <robh@kernel.org>