ARM i.MX boards: use CONFIG_MULTI_IRQ_HANDLER

Also, add handle_irq callbacks to machine descriptors.

Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
diff --git a/arch/arm/mach-mx5/board-mx51_babbage.c b/arch/arm/mach-mx5/board-mx51_babbage.c
index 11b0ff6..4bd5e87 100644
--- a/arch/arm/mach-mx5/board-mx51_babbage.c
+++ b/arch/arm/mach-mx5/board-mx51_babbage.c
@@ -420,6 +420,7 @@
 	.map_io = mx51_map_io,
 	.init_early = imx51_init_early,
 	.init_irq = mx51_init_irq,
+	.handle_irq = imx51_handle_irq,
 	.timer = &mx51_babbage_timer,
 	.init_machine = mx51_babbage_init,
 MACHINE_END