staging: comedi: aio_iiro_16: return input state in async command sample

Modify the sample data returned by the async command to include the current
state of the digital inputs. Otherwise the command needs to be canceled in
order for the user to do an (*insn_bits) operation to check the digital
inputs.

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>