ARM: Do not allow the probing of the local timer

Since this IRQ descriptor doesn't have an action registered, it is
allowed for probing via probe_irq_on/off() and it will be disabled by
the latter function. This patch sets the IRQ_NOPROBE status bit for the
local timer descriptor.
Signed-off-by: Varun Swara <Varun.Swara@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>

arch/arm/kernel/smp_twd.c

@@ -160,6 +160,7 @@ void __cpuinit twd_timer_setup(struct clock_event_device *clk)
 
 	/* Make sure our local interrupt controller has this enabled */
 	local_irq_save(flags);
+	irq_to_desc(clk->irq)->status |= IRQ_NOPROBE;
 	get_irq_chip(clk->irq)->unmask(clk->irq);
 	local_irq_restore(flags);