[media] adv7180: Pass correct flags to request_threaded_irq()

Most IRQ controllers support different types of interrupts. The adv7180
generates falling edge interrupts, so make sure to pass IRQF_TRIGGER_FALLING
to request_threaded_irq() so the IRQ controller is configured for the
correct mode.

Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Acked-by: Federico Vaga <federico.vaga@gmail.com>
Acked-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>