drm/i915: Fix SDVO connector and encoder get_hw_state functions

The connector associated with the encoder is considered active when the
output associtated with this connector is active on the encoder. The
encoder itself is considered active when either there is an active
output on  it or the  respective SDVO channel is active.
Having active outputs when the SDVO channel is inactive seems to be
inconsistent: such states can be found when intel_modeset_setup_hw_state()
collects the hardware state set by the BIOS.
This inconsistency will be fixed in intel_sanitize_crtc()
(when intel_crtc_update_dpms() is called), this however only happens
when the encoder is associated with a crtc.

This patch also reverts:

     commit bd6946e8
     Author: Daniel Vetter <daniel.vetter@ffwll.ch>
     Date:   Tue Apr 2 21:30:34 2013 +0200

         drm/i915: Fix sdvo connector get_hw_state function

Signed-off-by: Egbert Eich <eich@suse.de>
Suggested-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=63031


Cc: stable@vger.kernel.org
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>