Revert "ARM: dts: imx6qdl-apalis: Avoid underscore in node name"

The STMPE MFD device binding requires the child node to have a fixed
name, i.e. with '_', not '-'. Otherwise the stmpe_adc, stmpe_touchscreen
drivers will not be probed.

Fixes: 56086b5e80 ("ARM: dts: imx6qdl-apalis: Avoid underscore in node name")
Reviewed-by: Ahmad Fatoum <a.fatoum@pengutronix.de>
Signed-off-by: Max Krummenacher <max.krummenacher@toradex.com>
Signed-off-by: Shawn Guo <shawnguo@kernel.org>

arch/arm/boot/dts/imx6qdl-apalis.dtsi

@@ -315,7 +315,7 @@
 		/* ADC conversion time: 80 clocks */
 		st,sample-time = <4>;
 
-		stmpe_touchscreen: stmpe-touchscreen {
+		stmpe_touchscreen: stmpe_touchscreen {
 			compatible = "st,stmpe-ts";
 			/* 8 sample average control */
 			st,ave-ctrl = <3>;
@@ -332,7 +332,7 @@
 			st,touch-det-delay = <5>;
 		};
 
-		stmpe_adc: stmpe-adc {
+		stmpe_adc: stmpe_adc {
 			compatible = "st,stmpe-adc";
 			/* forbid to use ADC channels 3-0 (touch) */
 			st,norequest-mask = <0x0F>;