libcamera: controls: Generate and use fixed-sized Span types

Define Span types explicitly as either variable- or fixed-sized. This
introduces a new convention for defining Span dimensions in the property
and control value definitions and generates Span types as variable-sized
Span<T> or as fixed-sized Span<T,N>.

Signed-off-by: Christian Rauch <Rauch.Christian@gmx.de>
Reviewed-by: Jacopo Mondi <jacopo@jmondi.org>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>

include/libcamera/controls.h

@@ -168,7 +168,7 @@ public:
 
 		using V = typename T::value_type;
 		const V *value = reinterpret_cast<const V *>(data().data());
-		return { value, numElements_ };
+		return T{ value, numElements_ };
 	}
 
 #ifndef __DOXYGEN__