staging: comedi: addi_apci_2200: remove interrupt support code

This board does not have any interrupt capable devices. Remove the
unused interrupt support code.

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>