drm/i915: Assume eDP is always connected

We never registered any kind of lid notifier for eDP, so looking at the
lid status is pretty much bonkers. Let's just consider eDP always
connected instead.

Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20180717174216.22252-2-ville.syrjala@linux.intel.com
Reviewed-by: Rodrigo Vivi <rodrigo.vivi@intel.com>