drm/i915/crt: Force the initial probe after reset

Upon resume, like after a cold boot, we need to forcibly probe the
analog connector and cannot rely on the hotplug status.

Based on a patch by Takashi Iwai.

Reported-by: Stefan Dirsch <sndirsch@suse.de>
Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=26952
Tested-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>