arm64: dts: mediatek: mt8390-genio-700-evk: Configure touch vreg pins

Add a pinctrl configuration for the Touchscreen IC's power line
to make sure that the pin is configured as GPIO and to stop
relying on correct pin configuration from bootloader.

Signed-off-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>

arch/arm64/boot/dts/mediatek/mt8390-genio-700-evk.dts

@@ -195,6 +195,8 @@ touch0_fixed_3v3: regulator-5 {
 		gpio = <&pio 119 GPIO_ACTIVE_HIGH>;
 		enable-active-high;
 		vin-supply = <&reg_vsys>;
+		pinctrl-names = "default";
+		pinctrl-0 = <&touch_vreg_pins>;
 	};
 
 	usb_hub_fixed_3v3: regulator-6 {
@@ -953,6 +955,13 @@ pins-spi {
 		};
 	};
 
+	touch_vreg_pins: touch-avdd-pins {
+		pins-power {
+			pinmux = <PINMUX_GPIO120__FUNC_B_GPIO120>;
+			output-high;
+		};
+	};
+
 	touch_pins: touch-pins {
 		pins-irq {
 			pinmux = <PINMUX_GPIO6__FUNC_B_GPIO6>;