usb: ehci/ohci-platform: use SIMPLE_DEV_PM_OPS to support hibernation

ehci/ohci-platform just define .suspend/.resume functions for dev_pm_ops,
but in order to support both STR(suspend-to-ram) and hibernation, other
callbacks such as .freeze/.thaw are also required.

Registering all required callbacks for both STR and hibernation can
be done by SIMPLE_DEV_PM_OPS macro function.

Signed-off-by: Wonhong Kwon <wonhong.kwon@lge.com>
Acked-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>