usbcore: split suspend/resume for device and interfaces

This patch (as716b) splits up the core suspend and resume routines into
two parts each: one for handling devices and one for handling
interfaces.  The behavior of the parts should be the same as in the old
unified code.


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