staging: comedi: cb_pcimdda: remove ao_chans and ao_bits from boardinfo

This board always has 6, 16-bit analog outputs. There is no need to carry
this information in the boardinfo. Remove it.

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>