Use interrupts (with dedicated interrupt line) for irq_offload
instead of exception-based implementation.
That allows to implement IRQ_OFFLOAD without adding special code
to interrupt / exception path for IRQ_OFFLOAD handling and,
moreover, test the real interrupt code.
Signed-off-by: Eugeniy Paltsev <Eugeniy.Paltsev@synopsys.com>
Signed-off-by: Evgeniy Paltsev <PaltsevEvgeniy@gmail.com>