Please provide more information.
When you updated your drivers the M290X, which is a rebrand of the 8970M, was assigned the same Device ID so the name changed. However the performance of your GPU remains the same and has not changed. If you want the name to go back to M290X, you'll need to install your previous OEM drivers, then install the latest Crimson drivers on top of the previous drivers, without uninstalling them as you usually would first. Otherwise you can just ignore it as it will not decrease or increase your GPU performance, only the name of the GPU has changed due to the sharing of a Device ID with the same product rebranded from a previous generation.
You have not provided enough information, but what's more likely is the new drivers are not performing as well on your system, so i would recommend using Windows System Restore to regain that lost performance and revert to your previous driver.