staging: comedi: rtd520: rename CamelCase rtdBoard

Rename the CamelCase struct rtdBoard to rtd_boardinfo. Also, rename the
range10Start and rangeUniStart variables in the struct to range_bip10
and range_uni10.

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