usb/endpoint: Set release callback in the struct device_type instead of in the device itself directly

For following the way the rest of the usb core does, this patch is to change
the place of setting release callback.
Signed-off-by: Lan Tianyu <tianyu.lan@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>