On your PS4, go to...
- PlayStation Network/Account Management
- Account Information
- 2-Step Verification
It's easy-peasy. It'll give you the option to log out of all your PlayStation devices (and you'll be prompted to log back in with the authentication next time you log in on your Vita or whatever).
I highly, highly suggest doin' this. For the past month or so, not a day has gone by without a new post on NeoGAF by someone who says their account has been hacked. Protect yourself! Protect yourself before it's too laaaate!
Oh and here's Sony's FAQ on the new security measures. Noice.