usb/ub: deprecate & schedule for removal the "Low Performance USB Block" driver

Deprecate this driver. All devices which can be handled by this driver
can also be handled by the usb-storage driver.

Acked-By: Pete Zaitcev <zaitcev@redhat.com>
Cc: Jens Axboe <jaxboe@fusionio.com>
Signed-off-by: Sebastian Andrzej Siewior <sebastian@breakpoint.cc>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>