CMake instruction is not written in the document; grammar

*This may apply to other versions of the document and also other classes' document. So please check and fix them as well accordingly.

document link : https://doc.qt.io/qt-6/qcanbusdeviceinfo.html

This class only has a qmake instruction to use it, although the version of Qt is 6.x. 
We need to add CMake instruction too.