With AMD you just right click on the desktop, click AMD Radeon Settings, then click the Gaming tab, followed by Global Settings (or a game profile if you want to set it per game). On that page you click Frame rate Target Control on the lower left. Once it's enabled just adjust the slider to your desired FPS.
With Nvidia, fairly recent GeForce forum posts tell me they don't have such an option at the driver level in their control panel, unless they added it in with their latest drivers. You can however do it with Nvidia Inspector.https://forums.geforce.com/default/topic/989174/may-we-have-a-built-in-frame-rate-limiter-please-/
That said, I usually use RTSS, and only apply it via Radeon Settings when the game I'm capping won't work with RTSS. This btw is a good reason to set the cap per game, not globally. The reason I prefer RTSS is it has a much lower impact on RAM usage.http://www.guru3d.com/files-details/rtss-rivatuner-statistics-server-download.html