dt-bindings: input: Convert MELFAS MIP4 Touchscreen to DT schema

dt-bindings: input: Convert MELFAS MIP4 Touchscreen to DT schema

Convert the existing text-based DT bindings for MELFAS MIP4 Touchscreen
controller to a DT schema.

Signed-off-by: Ariel D'Alessandro <ariel.dalessandro@collabora.com>
Reviewed-by: Rob Herring (Arm) <robh@kernel.org>
Reviewed-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
Link: https://patch.msgid.link/20251001183809.83472-1-ariel.dalessandro@collabora.com
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>