drm/i915: Make intel_pm_setup take dev_priv

Function actually wants dev_priv so give it to it.

v2: Commit message. (Joonas Lahtinen)

Signed-off-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1480601805-14391-2-git-send-email-tvrtko.ursulin@linux.intel.com