staging: usbip: let client choose device configuration

Since usbip-host is now a device driver and the client
has full access to the shared device, it makes sense to
let the client choose device configuration.

Signed-off-by: Valentina Manea <valentina.manea.m@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>