drm/i915: Use atomic state and connector_type in i915_sink_src

DPMS is unreliable, use crtc->state.

Signed-off-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1466431059-8919-4-git-send-email-maarten.lankhorst@linux.intel.com


Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com>