staging: comedi: cb_pcimdda: add namespace to the driver

The structs, static data, and functions in this driver have
pretty generic names. Add namespace to everything to prevent
any problems.

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