staging: comedi: pcl724: tidy up the boardinfo

Convert the boardinfo declaration to C99 format and move it near the
struct 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>