sata_via: load DEVICE register when CTL changes

VIA controllers clear DEVICE register when IEN changes.  Make sure
DEVICE is updated along with CTL.

This change is separated from Joseph Chan's larger patch.

  http://thread.gmane.org/gmane.linux.kernel.commits.mm/40640

Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Joseph Chan <JosephChan@via.com.tw>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>