dt-bindings: touchscreen: Convert edt-ft5x06 to json-schema

Convert the EDT-FT5x06 to DT schema using json-schema.

Signed-off-by: Benjamin Gaignard <benjamin.gaignard@st.com>
Reviewed-by: Rob Herring <robh@kernel.org>
Link: https://lore.kernel.org/r/20200207084657.31195-1-benjamin.gaignard@st.com


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