staging: comedi: cb_pcidas: all boards have 16 analog input channels

All the boards supported by this driver have 16 analog input channels.
Remove this unnecessary information from the boardinfo.

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>