USB: OHCI: use pci_dev->revision

Commit ab1666c1 (USB: quirk PLL power down mode)
added code that reads the revision ID from the PCI configuration register while
it's stored by PCI subsystem in the 'revision' field of 'struct pci_dev'...

Signed-off-by: Sergei Shtylyov <sshtylyov@ru.mvista.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>