genirq: Walk the irq_data hierarchy when resending an interrupt

On resending an interrupt, we only check the outermost irqchip for
a irq_retrigger callback. However, this callback could be implemented
at an inner level. Use irq_chip_retrigger_hierarchy() in this case.

Reviewed-by: Valentin Schneider <valentin.schneider@arm.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>