I have a Toshiba SB-50 with an AMD Radeon R7 M260 2GB gpu. It is on the list of approved cards, but Premiere Pro cc 2015 will not recognize it. The card does show in Photoshop, although sometimes I have to restart the program. GPU Sniffer locates the card. Windows tells me I have the latest driver.
Never rely on Windows for driver updates, in your case go to AMD/ATI for your graphic driver update.