powerpc/85xx: Mark cascade irq IRQF_NO_THREAD

Cascade interrupt must run in hard interrupt context.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

arch/powerpc/platforms/85xx/mpc85xx_cds.c

@@ -177,7 +177,7 @@ static irqreturn_t mpc85xx_8259_cascade_action(int irq, void *dev_id)
 
 static struct irqaction mpc85xxcds_8259_irqaction = {
 	.handler = mpc85xx_8259_cascade_action,
-	.flags = IRQF_SHARED,
+	.flags = IRQF_SHARED | IRQF_NO_THREAD,
 	.name = "8259 cascade",
 };
 #endif /* PPC_I8259 */