Blackfin: SMP: convert to irq chip functions

void __cpuinit bfin_local_timer_setup(void)

{

#if defined(CONFIG_TICKSOURCE_CORETMR)

	struct irq_chip *chip = get_irq_chip(IRQ_CORETMR);

	struct irq_desc *desc = irq_to_desc(IRQ_CORETMR);

	bfin_coretmr_init();

	bfin_coretmr_clockevent_init();

	get_irq_chip(IRQ_CORETMR)->unmask(IRQ_CORETMR);

	chip->irq_unmask(&desc->irq_data);

#else

	/* Power down the core timer, just to play safe. */

	bfin_write_TCNTL(0);