drm/i915: Do not leak dev_priv->l3_parity.remap_info[]

Add intel_irq_fini() for placing the deinitialization code,
starting with freeing dev_priv->l3_parity.remap_info[].

Signed-off-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Cc: Mika Kuoppala <mika.kuoppala@intel.com>
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
Link: http://patchwork.freedesktop.org/patch/msgid/1493366319-18515-1-git-send-email-joonas.lahtinen@linux.intel.com