dev-arm: SMMUv3, enable interrupt interface

dev-arm: SMMUv3, enable interrupt interface

Users can set "irq_interface_enable" to allow software to program
SMMU_IRQ_CTRL and SMMU_IRQ_CTRLACK. This is required to boot Linux v5.4+
in a reasonable time. Notice the model does not implement architectural
interrupt sources, so no assertions will happen.

Change-Id: Ie138befdf5a204fe8fce961081c575c2166e22b9
Signed-off-by: Adrian Herrera <adrian.herrera@arm.com>
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/38555
Tested-by: kokoro <noreply+kokoro@google.com>
Reviewed-by: Andreas Sandberg <andreas.sandberg@arm.com>
Maintainer: Andreas Sandberg <andreas.sandberg@arm.com>