dt-bindings: interrupt-controller: idt,32434-pic: Add missing interrupts property

Interrupts property is required, so add it.

Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Link: https://lore.kernel.org/r/20210427224201.32285-1-tsbogend@alpha.franken.de


Signed-off-by: Rob Herring <robh@kernel.org>