libcamera: Use helper variable template for type traits

C++17 introduces helper variable templates for type traits, allowing
shortening std::is_foo<T>::value to std::is_foo_v<T>. Use them through
the code base.

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

include/libcamera/bound_method.h

@@ -63,7 +63,7 @@ public:
 	}
 	virtual ~BoundMethodBase() = default;
 
-	template<typename T, typename std::enable_if_t<!std::is_same<Object, T>::value> * = nullptr>
+	template<typename T, typename std::enable_if_t<!std::is_same_v<Object, T>> * = nullptr>
 	bool match(T *obj) { return obj == obj_; }
 	bool match(Object *object) { return object == object_; }