arm64: dts: qcom: sm8450-nagara: Add GPIO keys

With PMIC GPIOs now available, set up required pin settings and add
gpio-keys.
Signed-off-by: Konrad Dybcio <konrad.dybcio@linaro.org>
Signed-off-by: Bjorn Andersson <andersson@kernel.org>
Link: https://lore.kernel.org/r/20221229103212.984324-4-konrad.dybcio@linaro.org

arch/arm64/boot/dts/qcom/sm8450-sony-xperia-nagara.dtsi

@@ -27,6 +27,41 @@ chosen {
 		stdout-path = "serial0:115200n8";
 	};
 
+	gpio-keys {
+		compatible = "gpio-keys";
+		label = "gpio-keys";
+
+		pinctrl-names = "default";
+		pinctrl-0 = <&focus_n &snapshot_n &vol_down_n>;
+
+		key-camera-focus {
+			label = "Camera Focus";
+			linux,code = <KEY_CAMERA_FOCUS>;
+			gpios = <&pm8350b_gpios 8 GPIO_ACTIVE_LOW>;
+			debounce-interval = <15>;
+			linux,can-disable;
+			wakeup-source;
+		};
+
+		key-camera-snapshot {
+			label = "Camera Snapshot";
+			linux,code = <KEY_CAMERA>;
+			gpios = <&pm8350b_gpios 5 GPIO_ACTIVE_LOW>;
+			debounce-interval = <15>;
+			linux,can-disable;
+			wakeup-source;
+		};
+
+		key-volume-down {
+			label = "Volume Down";
+			linux,code = <KEY_VOLUMEDOWN>;
+			gpios = <&pm8350_gpios 6 GPIO_ACTIVE_LOW>;
+			debounce-interval = <15>;
+			linux,can-disable;
+			wakeup-source;
+		};
+	};
+
 	reserved-memory {
 		adsp_mem: memory@85700000 {
 			reg = <0x0 0x85700000 0x0 0x2800000>;
@@ -550,6 +585,32 @@ &pm8350_gpios {
 			  "NC",
 			  "NC",
 			  "PM8350_OPTION"; /* GPIO_10 */
+
+	vol_down_n: vol-down-n-state {
+		pins = "gpio6";
+		function = "normal";
+		power-source = <1>;
+		bias-pull-up;
+		input-enable;
+	};
+};
+
+&pm8350b_gpios {
+	snapshot_n: snapshot-n-state {
+		pins = "gpio5";
+		function = "normal";
+		power-source = <0>;
+		bias-pull-up;
+		input-enable;
+	};
+
+	focus_n: focus-n-state {
+		pins = "gpio8";
+		function = "normal";
+		power-source = <0>;
+		bias-pull-up;
+		input-enable;
+	};
 };
 
 &pm8450_gpios {