drm/radeon/kms: block RN50 from using 3D engine.

RN50/ES1000 is a cut-down rv100 chip used in the server market.
The 3D engine on these is either not there or unverified so refuse
any attempt to configure registers on it.

Signed-off-by: Dave Airlie <airlied@redhat.com>
2 files changed