arm64: dts: qcom: msm8916-samsung-a3u: Add touch key regulators

The touch key MCU and LED is supplied by two separate fixed regulators
that can be enabled through GPIO 86 and 60. Add them to the device tree.
Signed-off-by: Michael Srba <Michael.Srba@seznam.cz>
[stephan: extend commit message]
Signed-off-by: Stephan Gerhold <stephan@gerhold.net>
Link: https://lore.kernel.org/r/20210604172742.10593-2-stephan@gerhold.netSigned-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>

arch/arm64/boot/dts/qcom/msm8916-samsung-a3u-eur.dts

@@ -20,6 +20,37 @@ reg_panel_vdd3: regulator-panel-vdd3 {
 		pinctrl-names = "default";
 		pinctrl-0 = <&panel_vdd3_default>;
 	};
+
+	reg_touch_key: regulator-touch-key {
+		compatible = "regulator-fixed";
+		regulator-name = "touch_key";
+		regulator-min-microvolt = <2800000>;
+		regulator-max-microvolt = <2800000>;
+
+		gpio = <&msmgpio 86 GPIO_ACTIVE_HIGH>;
+		enable-active-high;
+
+		pinctrl-names = "default";
+		pinctrl-0 = <&tkey_en_default>;
+	};
+
+	reg_key_led: regulator-key-led {
+		compatible = "regulator-fixed";
+		regulator-name = "key_led";
+		regulator-min-microvolt = <3300000>;
+		regulator-max-microvolt = <3300000>;
+
+		gpio = <&msmgpio 60 GPIO_ACTIVE_HIGH>;
+		enable-active-high;
+
+		pinctrl-names = "default";
+		pinctrl-0 = <&tkey_led_en_default>;
+	};
+};
+
+&touchkey {
+	vcc-supply = <&reg_touch_key>;
+	vdd-supply = <&reg_key_led>;
 };
 
 &accelerometer {
@@ -81,6 +112,22 @@ panel_vdd3_default: panel-vdd3-default {
 		bias-disable;
 	};
 
+	tkey_en_default: tkey-en-default {
+		pins = "gpio86";
+		function = "gpio";
+
+		drive-strength = <2>;
+		bias-disable;
+	};
+
+	tkey_led_en_default: tkey-led-en-default {
+		pins = "gpio60";
+		function = "gpio";
+
+		drive-strength = <2>;
+		bias-disable;
+	};
+
 	ts_int_default: ts-int-default {
 		pins = "gpio13";
 		function = "gpio";