CHV has two display PHYs so there are also two cmnlane power wells. Add
the approriate code to power the wells up/down.
Like on VLV we do the cmnreset assert/deassert and the DPLL refclock
enabling at approriate times.
This code actually works on my bsw.
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com> Reviewed-by: Imre Deak <imre.deak@intel.com> Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>