staging: comedi: icp_multi: remove interrupt support

The interrupt handler in this driver doesn't do anything other than
read the interrupt status register. Since I can't locate a datasheet
for the board, remove the useless interrupt support code.

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>