libcamera: Use the Size class through libcamera

Several of our structures include width and height fields that model a
size while we have a Size class for that purpose. Use the Size class
through libcamera, and give it a toString() method like other geometry
and format classes.

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

src/libcamera/camera.cpp

@@ -131,7 +131,7 @@ bool CameraConfiguration::isValid() const
 	for (auto const &it : config_) {
 		const StreamConfiguration &conf = it.second;
 
-		if (conf.width == 0 || conf.height == 0 ||
+		if (conf.size.width == 0 || conf.size.height == 0 ||
 		    conf.pixelFormat == 0 || conf.bufferCount == 0)
 			return false;
 	}