drm/i915: Set SSC frequency for 8xx chips correctly

All 8xx class chips have the 66/48 split, not just 855.

Signed-off-by: Ma Ling <ling.ma@intel.com>
Reviewed-by: Jesse Barnes <jbarnes@virtuousgeek.org>
Signed-off-by: Eric Anholt <eric@anholt.net>
1 file changed