media: pci/ivtv: Use managed version of pci_enable_device

If there is any error during probing, we should probably leave the
device in its previous state.

pcim_ will take care of this.

Signed-off-by: Ricardo Ribalda <ribalda@chromium.org>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>