arm64: dts: qcom: sm8550-qrd: enable PMIC Volume and Power buttons

The Volume Down & Power buttons are controlled by the PMIC via
the PON hardware, and the Volume Up is connected to a PMIC gpio.

Enable the necessary hardware and setup the GPIO state for the
Volume Up gpio key.

Reviewed-by: Konrad Dybcio <[e-mail]>
Signed-off-by: Neil Armstrong <[e-mail]>
Signed-off-by: Bjorn Andersson <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]

arch/arm64/boot/dts/qcom/sm8550-qrd.dts

···
 		stdout-path = "serial0:115200n8";
 	};
 
+	gpio-keys {
+		compatible = "gpio-keys";
+
+		pinctrl-0 = <&volume_up_n>;
+		pinctrl-names = "default";
+
+		key-volume-up {
+			label = "Volume Up";
+			linux,code = <KEY_VOLUMEUP>;
+			gpios = <&pm8550_gpios 6 GPIO_ACTIVE_LOW>;
+			debounce-interval = <15>;
+			linux,can-disable;
+			wakeup-source;
+		};
+	};
+
 	pmic-glink {
 		compatible = "qcom,sm8550-pmic-glink", "qcom,pmic-glink";
 		#address-cells = <1>;
···
 	};
 };
 
+&pm8550_gpios {
+	volume_up_n: volume-up-n-state {
+		pins = "gpio6";
+		function = "normal";
+		power-source = <1>;
+		bias-pull-up;
+		input-enable;
+	};
+};
+
 &pm8550_pwm {
 	status = "okay";
 
···
 &pm8550b_eusb2_repeater {
 	vdd18-supply = <&vreg_l15b_1p8>;
 	vdd3-supply = <&vreg_l5b_3p1>;
+};
+
+&pon_pwrkey {
+	status = "okay";
+};
+
+&pon_resin {
+	linux,code = <KEY_VOLUMEDOWN>;
+
+	status = "okay";
 };
 
 &pcie_1_phy_aux_clk {