[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 c642b8391cf8efc3622cc97329a0f46e7cbb70b8 changed the behaviour of
IRQ_PER_CPU interrupts, which previously weren't checked for IRQ_DISABLED.

Signed-off-by: Kyle McMartin <kyle@mcmartin.ca>
diff --git a/arch/parisc/kernel/irq.c b/arch/parisc/kernel/irq.c
index 76ce5e3..23ef950 100644
--- a/arch/parisc/kernel/irq.c
+++ b/arch/parisc/kernel/irq.c
@@ -397,7 +397,7 @@
 	}
 
 	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;