staging: comedi: addi_data: remove pr_TTLRangelist

All the addi driver ttl subdevices use the range table
'range_digital' provided by the comedi core. The boardinfo
value  'pr_TTLRangeList' is not used by the drivers. Remove
the unused range tables and the boardinfo pointer.

The unused range tables don't make sense anyway...

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