staging: unisys: fix CamelCase names in struct pci_id

Fix CamelCase names:

Domain => domain
Bus => bus
Slot => slot
Func => func
Reserved => reserved

Signed-off-by: Benjamin Romer <benjamin.romer@unisys.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>