ARM: highbank: convert to CONFIG_MULTI_IRQ_HANDLER

Convert the highbank platform to be using the gic_handle_irq
function as its primary interrupt handler.

Cc: Rob Herring <rob.herring@calxeda.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
diff --git a/arch/arm/mach-highbank/highbank.c b/arch/arm/mach-highbank/highbank.c
index b82dcf0..89bdf00 100644
--- a/arch/arm/mach-highbank/highbank.c
+++ b/arch/arm/mach-highbank/highbank.c
@@ -140,6 +140,7 @@
 	.map_io		= highbank_map_io,
 	.init_irq	= highbank_init_irq,
 	.timer		= &highbank_timer,
+	.handle_irq	= gic_handle_irq,
 	.init_machine	= highbank_init,
 	.dt_compat	= highbank_match,
 MACHINE_END