PCI: remove pci_get_device_reverse from calgary driver

This isn't needed, we can just walk the devices in bus order with no
problems at all, as we really want to remove pci_get_device_reverse from
the kernel tree.

Acked-by: Muli Ben-Yehuda <muli@il.ibm.com>
Cc: Jon Mason <jdmason@kudzu.us>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>