drm/i915/vlv: move DPIO common reset de-assert into __vlv_set_power_well

We need to do this anytime we power gate the DPIO common well.

Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>