staging: comedi: ni_labpc: tidy up range table declarations

Tidy up all the tables used to indicate the bipolar/unipolar
type of the range. the gain bits used to set the range, and the
comedi_lrange.

Remove a couple unnecessary #define's used to indicate the size
of the tables as well as some unnecessary comments.

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