Screen goes black for the oculus rift when changing the Screen percentage on an AMD 200 Series graphics card

When setting the mirror mode and the screen percentage the screen on the oculus rift will go black if you are using an AMD 200 series card.

1. Open a the editor on a machine with an AMD 200 series graphics card
2. Click VR preview
3. Press the '~' key to bring up the command console
4. Type in "hmd mirror mode 1" (no quotes)
5. Press enter
6. Press the '~' key to bring up the command console
7. Type in "hmd sp 101" (no quotes)
8. Notice that the screen on the oculus rift has gone black
9. Press the '~' key to bring up the command console
10. Type in "hmd sp 100" (no quotes)
11. Notice that the screen should return to normal

Expected: the screen percentage should change and the oculus should not go black
Result: screen for the oculus goes black