drm/radeon: add support for Richland APUs

Richland APUs are a new version of the Trinity APUs
with performance and power management improvements.

Reviewed-by: Jerome Glisse <jglisse@redhat.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Cc: stable@vger.kernel.org
1 file changed