Copy the approach taken by gfx8, which simplifies the code, and set the
instance index properly. The latter is required for debugging, e.g. for
reading wave status by UMR.
Signed-off-by: NNicolai Hähnle <nicolai.haehnle@amd.com>
Reviewed-by: NAlex Deucher <alexander.deucher@amd.com>
Signed-off-by: NAlex Deucher <alexander.deucher@amd.com>