usbcore: rename usb_suspend_device to usb_port_suspend

This revised patch (as715b) renames usb_suspend_device to
usb_port_suspend, usb_resume_device to usb_port_resume, and
finish_device_resume to finish_port_resume.  There was no objection to
the original version of the patch so this should be okay to apply.

The revision was needed only because I have re-arranged the order of the
earlier patches.

Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>