staging: comedi: addi_apci_16xx: redefine the boardinfo

Currently this driver uses the struct addi_board from the addi-data
"common" code to define the boardinfo. This struct contains a lot
of information that is not used in this driver.

Introduce a private struct in the driver that just contains the
needed information.

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>