Raven2 does not enable all of the CG flags that raven1 does.

v2: rebase (Alex)
Signed-off-by: Huang Rui <ray.huang@amd.com>
Reviewed-by: Feifei Xu <Feifei.Xu@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>