ide: Fix ordering of procfs registry.

We must ensure that ide_proc_port_register_devices() occurs on an
interface before ide_proc_register_driver() executes for that
interfaces drives.

Therefore defer the registry of the driver device objects backed by
ide_bus_type until after ide_proc_port_register_devices() has run
and thus all of the drive->proc procfs directory pointers have been
setup.

Signed-off-by: Wolfram Sang <w.sang@pengutronix.de>
Signed-off-by: David S. Miller <davem@davemloft.net>