ipa: raspberrypi: Add sensor temperature to DeviceStatus

Add an optional sensor_temperature field to the DeviceStatus structure. If a
temperature measurement is available for a frame, the value is returned out
through the SensorTemperature control in the Request metadata.

Additionally, provide the sensor temperature value from the std::ostream &operator<<
overload.

Signed-off-by: Naushir Patuck <naush@raspberrypi.com>
Reviewed-by: Kieran Bingham <kieran.bingham@ideasonboard.com>
Reviewed-by: David Plowman <david.plowman@raspberrypi.com>
Signed-off-by: Kieran Bingham <kieran.bingham@ideasonboard.com>

src/ipa/raspberrypi/controller/device_status.h

@@ -7,6 +7,7 @@
 #pragma once
 
 #include <iostream>
+#include <optional>
 
 #include <libcamera/base/utils.h>
 
@@ -36,4 +37,6 @@ struct DeviceStatus {
 	double aperture;
 	/* proportional to brightness with 0 = no flash, 1 = maximum flash */
 	double flash_intensity;
+	/* Sensor reported temperature value (in degrees) */
+	std::optional<double> sensor_temperature;
 };