USB: Au1xxx-usb: suspend/resume support.

Copy the OHCI/EHCI PM callbacks of the PCI implementation since
they work equally well on Au1xxx hardware.

Tested on Au1200.

Signed-off-by: Manuel Lauss <mano@roarinelk.homelinux.net>
Cc: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>