libcamera: request: Add metadata information

A new ControlList container is needed to hold metadata coming out of
the IPA. The list of supported controls in this list is expected to
grow, so for now do not add a validator for the list.

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

include/libcamera/request.h

@@ -37,6 +37,7 @@ public:
 	~Request();
 
 	ControlList &controls() { return *controls_; }
+	ControlList &metadata() { return *metadata_; }
 	const std::map<Stream *, Buffer *> &buffers() const { return bufferMap_; }
 	int addBuffer(std::unique_ptr<Buffer> buffer);
 	Buffer *findBuffer(Stream *stream) const;
@@ -58,6 +59,7 @@ private:
 	Camera *camera_;
 	CameraControlValidator *validator_;
 	ControlList *controls_;
+	ControlList *metadata_;
 	std::map<Stream *, Buffer *> bufferMap_;
 	std::unordered_set<Buffer *> pending_;