[MIPS] use generic_handle_irq, handle_level_irq, handle_percpu_irq

Further incorporation of generic irq framework.  Replacing __do_IRQ()
by proper flow handler would make the irq handling path a bit simpler
and faster.

* use generic_handle_irq() instead of __do_IRQ().
* use handle_level_irq for obvious level-type irq chips.
* use handle_percpu_irq for irqs marked as IRQ_PER_CPU.
* setup .eoi routine for irq chips possibly used with handle_percpu_irq.

Signed-off-by: Atsushi Nemoto <anemo@mba.ocn.ne.jp>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

arch/mips/kernel/irq-msc01.c

@@ -117,6 +117,7 @@ struct irq_chip msc_levelirq_type = {
 	.mask = mask_msc_irq,
 	.mask_ack = level_mask_and_ack_msc_irq,
 	.unmask = unmask_msc_irq,
+	.eoi = unmask_msc_irq,
 	.end = end_msc_irq,
 };
 
@@ -126,6 +127,7 @@ struct irq_chip msc_edgeirq_type = {
 	.mask = mask_msc_irq,
 	.mask_ack = edge_mask_and_ack_msc_irq,
 	.unmask = unmask_msc_irq,
+	.eoi = unmask_msc_irq,
 	.end = end_msc_irq,
 };