drm/i915: fix hotplug event bit tracking

drm/i915: fix hotplug event bit tracking

commit 142e239849c800f9dc23f828762873073f612d3f
Author: Egbert Eich <eich@suse.de>
Date:   Thu Apr 11 15:57:57 2013 +0200

    drm/i915: Add bit field to record which pins have received HPD events (v3)

added a bit field for hotplug event tracking. There ended up being three
different v3 of the patch: [1], [2], and [3]. Apparently [1] was the
correct one, but some frankenstein combination of the three got
committed, which reversed the logic for setting the hotplug bits and
misplaced a continue statement, skipping the hotplug irq storm handling
altogether.

This lead to broken hotplug detection, bisected to
commit 321a1b3026ea194dd084cf3bda1e235b2986b0af
Author: Egbert Eich <eich@suse.de>
Date:   Thu Apr 11 16:00:26 2013 +0200

    drm/i915: Only reprobe display on encoder which has received an HPD event (v2)

which uses the incorrectly set hotplug event bits.

Fix the mess.

[1] http://mid.gmane.org/1366112220-7638-6-git-send-email-eich@suse.de
[2] http://mid.gmane.org/1365688677-13682-1-git-send-email-eich@suse.de
[3] http://mid.gmane.org/1365688996-13874-1-git-send-email-eich@suse.de

Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>