libcamera: controls: Remove the unused ControlList::update() method

The ControlList::update() method is unused. While it is meant to fulfil
a need of applications, having no user means that it is most probably
not correctly designed. Remove the method, we will add it back later if
needed.

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

include/libcamera/controls.h

@@ -158,8 +158,6 @@ public:
 		val->set<T>(value);
 	}
 
-	void update(const ControlList &list);
-
 private:
 	const ControlValue *find(const ControlId &id) const;
 	ControlValue *find(const ControlId &id);