[PARISC] timer interrupt should not be IRQ_DISABLED

The timer interrupt had accidentally been marked IRQ_DISABLED since
IRQ_PER_CPU had been OR-ed in, instead of set. This had been working
by accident for quite a while.

Commit c642b839 changed the behaviour of
IRQ_PER_CPU interrupts, which previously weren't checked for IRQ_DISABLED.
Signed-off-by: NKyle McMartin <kyle@mcmartin.ca>

arch/parisc/kernel/irq.c

@@ -397,7 +397,7 @@ static void claim_cpu_irqs(void)
 	}
 
 	irq_desc[TIMER_IRQ].action = &timer_action;
-	irq_desc[TIMER_IRQ].status |= IRQ_PER_CPU;
+	irq_desc[TIMER_IRQ].status = IRQ_PER_CPU;
 #ifdef CONFIG_SMP
 	irq_desc[IPI_IRQ].action = &ipi_action;
 	irq_desc[IPI_IRQ].status = IRQ_PER_CPU;