[media] s5c73m3: Add missing subdev .unregistered callback

This is needed to free any resources requested in
the .registered subdev op.

Signed-off-by: Sylwester Nawrocki <s.nawrocki@samsung.com>
Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
1 file changed