powerpc: Fix pq2fads irq handling with PREEMPT_RT

Fix interrupt threading issue on pq2fads when running with CONFIG_PREEMPT_RT
Signed-off-by: Rune Torgersen <runet@innovsys.com>
Signed-off-by: Kumar Gala <galak@kernel.crashing.org>

arch/powerpc/platforms/82xx/pq2ads-pci-pic.c

@@ -109,7 +109,7 @@ static int pci_pic_host_map(struct irq_host *h, unsigned int virq,
 {
 	get_irq_desc(virq)->status |= IRQ_LEVEL;
 	set_irq_chip_data(virq, h->host_data);
-	set_irq_chip(virq, &pq2ads_pci_ic);
+	set_irq_chip_and_handler(virq, &pq2ads_pci_ic, handle_level_irq);
 	return 0;
 }