staging: comedi: pcl711: convert boardinfo flags to bit-fields

To save a bit of space, convert the 'is_pcl711b' and 'is_8112' flags
in the boardinfo to bit-fields.

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>