WaDisable4x2SubspanOptimization isn't listed for VLV in the workaround
database, but BSpec says that the relevant bit must be set. Add a
comment to remind people of this.
Signed-off-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: NRodrigo Vivi <rodrigo.vivi@gmail.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>