drm/i915/cnl: Inherit RPS stuff from previous platforms.

Apparently no change on RPS stuff from previous platforms.

v2: Merging to rps related patches in one and also adding
    missed cases.

Cc: David Weinehall <david.weinehall@intel.com>
Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
Reviewed-by: David Weinehall <david.weinehall@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1499373673-25066-1-git-send-email-rodrigo.vivi@intel.com