[Blackfin] arch: fix bug - linux-2.6.24 (delayed) disable IRQ feature not functional for handle_simple_irq

Bypass delayed disable feature by implementing chip->disable and
chip->enable.

http://lkml.org/lkml/2008/2/19/115

Signed-off-by: Michael Hennerich <michael.hennerich@analog.com>
Signed-off-by: Bryan Wu <cooloney@kernel.org>

arch/blackfin/mach-common/ints-priority.c

@@ -213,6 +213,9 @@ static struct irq_chip bfin_internal_irqchip = {
 	.ack = ack_noop,
 	.mask = bfin_internal_mask_irq,
 	.unmask = bfin_internal_unmask_irq,
+	.mask_ack = bfin_internal_mask_irq,
+	.disable = bfin_internal_mask_irq,
+	.enable = bfin_internal_unmask_irq,
 #ifdef CONFIG_PM
 	.set_wake = bfin_internal_set_wake,
 #endif