staging: comedi: pcl816: remove 'ao_chanlist' from boardinfo

This member in the boardinfo is the same for all board types. Remove
it.

The comedi core will initalize the subdevice len_chanlist to 1 if it
is not set by the driver so remove the unnecessary initialization.

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