staging: comedi: ni_daq_700: remove the #ifdef'ed out irq code

The irq code is not compiled in due to the '#ifdef incomplete'.
And, as stated, it's not even complete. Just remove it.

Signed-off-by: H Hartley Sweeten <hsweeten@visionengravers.com>
Cc: Ian Abbott <abbotti@mev.co.uk>
Cc: Frank Mori Hess <fmhess@users.sourceforge.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>