staging: comedi: addi_apci_1516: remove use of struct addi_board

The only boardinfo needed in this driver only consists of 6 data
values. The "common" addi_board has a lot of unnecessary bloat.

Create a local struct for this drivers boardinfo and remove the
need for struct addi_board in the "common" code.

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>