tty: Convert the USB drivers to the new icount interface

Simple pasting job using the new ops function. Also fix a couple of devices
directly returning the internal struct (which happens at this point to match
for the fields that matter but isn't correct or futureproof)

Signed-off-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>