drm/i915: fold the queue_work into intel_hpd_irq_handler

Everywhere the same.

Note that this patch leaves unnecessary braces behind, but the next
patch will kill those all anyway (including the if itself) so I've
figured I can keep the diff a bit smaller.

v2: Rebase on top of the i965g/gm sdvo hpd fix.

Cc: Egbert Eich <eich@suse.de>
Reviewed-by: Egbert Eich <eich@suse.de>
Reviewed-by: Paulo Zanoni <paulo.r.zanoni@intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>