arm64: dts: imx8mq-librem5: add pinctrl for the touchscreen description

In order for the touchscreen interrupt line to work, describe it properly.
Otherwise it can work if defaults are ok, but we cannot be sure.

Fixes: 8f0216b0 ("arm64: dts: Add a device tree for the Librem 5 phone")
Signed-off-by: Martin Kepplinger <martin.kepplinger@puri.sm>
Reviewed-by: Krzysztof Kozlowski <krzk@kernel.org>
Signed-off-by: Shawn Guo <shawnguo@kernel.org>

arch/arm64/boot/dts/freescale/imx8mq-librem5.dtsi

@@ -459,6 +459,13 @@ MX8MQ_IOMUXC_GPIO1_IO10_GPIO1_IO10	0x01C0
 		>;
 	};
 
+	pinctrl_touch: touchgrp {
+		fsl,pins = <
+			/* TP_INT */
+			MX8MQ_IOMUXC_ENET_RD1_GPIO1_IO27	0x80
+		>;
+	};
+
 	pinctrl_typec: typecgrp {
 		fsl,pins = <
 			/* TYPEC_MUX_EN */
@@ -880,6 +887,8 @@ led_backlight: led@0 {
 	touchscreen@38 {
 		compatible = "edt,edt-ft5506";
 		reg = <0x38>;
+		pinctrl-names = "default";
+		pinctrl-0 = <&pinctrl_touch>;
 		interrupt-parent = <&gpio1>;
 		interrupts = <27 IRQ_TYPE_EDGE_FALLING>;
 		touchscreen-size-x = <720>;