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

It is recommended not to use underscore in node names.

Change it to dash.

Signed-off-by: Fabio Estevam <[e-mail]>
Signed-off-by: Shawn Guo <[e-mail]>

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

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