With deferred fbdev setup we always need to forward hotplug events,
even if fbdev isn't fully set up yet. Otherwise the deferred setup
will neer happen.

Originally this check was added in

commit c45eb4fe (tag: drm-intel-next-fixes-2016-08-05)
Author: Chris Wilson <chris@chris-wilson.co.uk>
Date:   Wed Jul 13 18:34:45 2016 +0100

    drm/i915/fbdev: Check for the framebuffer before use

But the specific case of the hotplug function blowing up was fixed in

commit 50c3dc97
Author: Daniel Vetter <daniel.vetter@ffwll.ch>
Date:   Fri Jun 27 17:19:22 2014 +0200

    drm/fb-helper: Fix hpd vs. initial config races

Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Cc: Mika Kuoppala <mika.kuoppala@intel.com>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: NMaarten Lankhorst <maarten.lankhorst@linux.intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20170706130023.28417-1-daniel.vetter@ffwll.ch