For internal APIs passing dev_priv is preferred to reduce indirections,
so convert over a few DDI PHY, CDCLK helpers.

No functional change.
Signed-off-by: NImre Deak <imre.deak@intel.com>
Acked-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: NDavid Weinehall <david.weinehall@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1459515767-29228-10-git-send-email-imre.deak@intel.com