staging: comedi: addi_apci_3120: remove unused struct definition

The struct str_AnalogReadInformation is not used in this driver.
Remove it.

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>