IOC3: Switch to pci refcounting safe APIs

Convert the IOC3 driver to use ref counting pci interfaces so that we can
obsolete the (usually unsafe) pci_find_{slot/device} interfaces and avoid
future authors writing hotplug-unsafe device drivers.

Signed-off-by: Alan Cox <alan@redhat.com>

Build fixes:
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Signed-off-by: Jeff Garzik <jeff@garzik.org>