cciss: Add IRQF_SHARED back in for the non-MSI(X) interrupt handler

IRQF_SHARED is required for older controllers that don't support MSI(X)
and which may end up sharing an interrupt.

Also remove deprecated IRQF_DISABLED.

Signed-off-by: Stephen M. Cameron <scameron@beardog.cce.hp.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>