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

Documentation/devicetree/bindings/iio/adc/st,stmpe-adc.yaml

@@ -13,8 +13,7 @@ description:
   This ADC forms part of an ST microelectronics STMPE multifunction device .
   The ADC is shared with the STMPE touchscreen. As a result some ADC related
   settings are specified in the parent node.
-  The node name myst be stmpe_adc and should be a child node of the stmpe node
-  to which it belongs.
+  The node should be a child node of the stmpe node to which it belongs.
 
 properties:
   compatible: