libcamera: Declare empty virtual destructors as defaulted

The base class of polymorphic classes is required to declare a
destructor. Several of these are empty, and can thus be declared as
defaulted.

Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: Umang Jain <email@uajain.com>
Reviewed-by: Kieran Bingham <kieran.bingham@ideasonboard.com>

src/cam/options.h

@@ -73,7 +73,7 @@ public:
 	{
 	};
 
-	virtual ~KeyValueParser() {}
+	virtual ~KeyValueParser() = default;
 
 	bool addOption(const char *name, OptionType type, const char *help,
 		       OptionArgument argument = ArgumentNone);