libcamera: camera_sensor: Generate a sensor ID

The ID is generated from information in the firmware description of the
sensor if available or from module and model information if the sensor
is virtual (for example VIMC).

Signed-off-by: Niklas Söderlund <niklas.soderlund@ragnatech.se>
Reviewed-by: Jacopo Mondi <jacopo@jmondi.org>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>

include/libcamera/internal/camera_sensor.h

@@ -67,11 +67,14 @@ protected:
 	std::string logPrefix() const override;
 
 private:
+	int generateId();
+
 	const MediaEntity *entity_;
 	std::unique_ptr<V4L2Subdevice> subdev_;
 	unsigned int pad_;
 
 	std::string model_;
+	std::string id_;
 
 	V4L2Subdevice::Formats formats_;
 	Size resolution_;