irqchip/gic-v3: Do not check trigger configuration of partitionned LPIs

We cannot know the trigger of partitionned PPIs ahead of time
(when we instanciate the partitions), so let's not check them
early.

Reported-by: JeffyChen <jeffy.chen@rock-chips.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>