ARM: imx5: tzic_init_irq() can directly be .init_irq hook

After i.MX51 supports DT only, tzic_init_irq() can figure out the
tzic_base on its own.  Thus, it can directly be .init_irq hook, and
mx51[53]_init_irq() can be saved.

Signed-off-by: Shawn Guo <shawn.guo@freescale.com>
diff --git a/arch/arm/mach-imx/mach-imx50.c b/arch/arm/mach-imx/mach-imx50.c
index b899c0b..66e537b 100644
--- a/arch/arm/mach-imx/mach-imx50.c
+++ b/arch/arm/mach-imx/mach-imx50.c
@@ -30,7 +30,7 @@
 
 DT_MACHINE_START(IMX50_DT, "Freescale i.MX50 (Device Tree Support)")
 	.map_io		= mx53_map_io,
-	.init_irq	= mx53_init_irq,
+	.init_irq	= tzic_init_irq,
 	.init_machine	= imx50_dt_init,
 	.dt_compat	= imx50_dt_board_compat,
 	.restart	= mxc_restart,