Use devm_request_irq to simplify error handling path,
when probe smmu device.

Also devm_{request|free}_irq when init or destroy domain context.
Signed-off-by: Peng Fan <van.freenix@gmail.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Robin Murphy <robin.murphy@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>