dt-bindings: iio: adc: stmpe: Remove node name requirement

STMPE driver does not require a specific node name anymore, only the
compatible is checked, update binding according to this.

Signed-off-by: Francesco Dolcini <francesco.dolcini@toradex.com>
Acked-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Link: https://lore.kernel.org/r/20220712163345.445811-5-francesco.dolcini@toradex.com


Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>