staging: comedi: pcl818: convert boardinfo declaration to C99 format

To reduce editing errors and make the data more maintainable, convert
the boardinfo declaration to C99 format.

For aesthetics, move the declaration closer to the definition and remove
the unnecessary comments in the definition.

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>