EA announces that the flickering issue impacting multi-GPU systems introduced by the recent Battlefield 4 patch will be fixed tomorrow (thanks AngusThermopyle). Here's word from the Battlefield Battlelog:

Just a quick note that we aim to fix the recent SLI/CrossFire flickering issue in a custom patch planned to go live Dec 20 (this might change.) We will get back with full patch notes as the update rolls out. During this deploy, there will be a period of downtime in multiplayer on all platforms. As always, visit the BF4 Control Room for the latest info.