staging: comedi: drivers: use comedi_legacy_detach()

Use comedi_legacy_detach() to release the I/O region requested
by these drivers.

Signed-off-by: H Hartley Sweeten <hsweeten@visionengravers.com>
Reviewed-by: Ian Abbott <abbotti@mev.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>