libcamera: control_ids: Generate map of all supported controls

In order to deserialise a ControlList, we will need to lookup ControlId
instances based on their numerical ID. Generate a global map from the
controls definitions to support such a lookup.

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

src/libcamera/controls.cpp

@@ -355,6 +355,15 @@ std::string ControlRange::toString() const
 	return ss.str();
 }
 
+/**
+ * \typedef ControlIdMap
+ * \brief A map of numerical control ID to ControlId
+ *
+ * The map is used by ControlList instances to access controls by numerical
+ * IDs. A global map of all libcamera controls is provided by
+ * controls::controls.
+ */
+
 /**
  * \typedef ControlInfoMap
  * \brief A map of ControlId to ControlRange