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-imx51.c b/arch/arm/mach-imx/mach-imx51.c
index b8cd968..a849d43 100644
--- a/arch/arm/mach-imx/mach-imx51.c
+++ b/arch/arm/mach-imx/mach-imx51.c
@@ -37,7 +37,7 @@
 DT_MACHINE_START(IMX51_DT, "Freescale i.MX51 (Device Tree Support)")
 	.map_io		= mx51_map_io,
 	.init_early	= imx51_init_early,
-	.init_irq	= mx51_init_irq,
+	.init_irq	= tzic_init_irq,
 	.init_machine	= imx51_dt_init,
 	.init_late	= imx51_init_late,
 	.dt_compat	= imx51_dt_board_compat,