I recently came across this part of the EA games site where you can download DLC for their old games for free. Some of those games are also on GOG, namely Mirror's Edge, Dragon Age and Crysis.

There's a bit of everything from Soundtracks, game content, Artbooks...etc.

Link is here: https://help.ea.com/en-us/help/faq/dlc-for-classic-games/

Enjoy :)