lled between when the dummy driver is bound to the card
and when the children devices are being shut down.  Add dummy_start_iso
and friends.

On the other hand, .enable, .set_config_rom, .read_csr, write_csr do not
need to be implemented by the dummy driver, as commented.

Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
.¾õS›ix