drm/i915: Move long hpd handling into the hotplug work

drm/i915: Move long hpd handling into the hotplug work

We can't rely on connector->status in the detect() hook if the long hpd
was already handled by the dig_port_work as that won't update
connector->status. Thus we have to defer the long hpd handling entirely
until the hotplug work runs to avoid the double long hpd handling
the "detect_done" flag is trying to prevent.

We'll start to depend on connector->status being up to date in a
following patch.

Cc: Damien Cassou <damien@cassou.me>
Cc: freedesktop.org@gp.mailgun.org
Cc: Arno <blouin.arno@gmail.com>
Cc: Shubhangi Shrivastava <shubhangi.shrivastava@intel.com>
Cc: Sivakumar Thulasimani <sivakumar.thulasimani@intel.com>
Cc: Ander Conselvan de Oliveira <conselvan2@gmail.com>
Cc: stable@vger.kernel.org
Tested-by: Arno <blouin.arno@gmail.com>
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=83348
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1475481316-8194-1-git-send-email-ville.syrjala@linux.intel.com
Reviewed-by: Ander Conselvan de Oliveira <conselvan2@gmail.com>
(cherry picked from commit 27d4efc5591a5853de54713bc717de73c8951e17)
Signed-off-by: Jani Nikula <jani.nikula@intel.com>