drm/i915: Attach the pci match data to the device upon creation

Attach our device_info to the our i915 private on creation so that it is
always available for inspection.

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Michal Wajdeczko <michal.wajdeczko@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20180905140921.17467-1-chris@chris-wilson.co.uk