ARM: provide a late_initcall hook for platform initialization

This allows platforms to set up things that need to be done at
late_initcall time.
Signed-off-by: Shawn Guo <shawn.guo@linaro.org>
Tested-by: Robert Lee <rob.lee@linaro.org>
Tested-by: Stephen Warren <swarren@wwwdotorg.org>
Reviewed-by: H Hartley Sweeten <hsweeten@visionengravers.com>
Acked-by: Russell King <rmk+kernel@arm.linux.org.uk>

arch/arm/include/asm/mach/arch.h

@@ -43,6 +43,7 @@ struct machine_desc {
 	void			(*init_irq)(void);
 	struct sys_timer	*timer;		/* system tick timer	*/
 	void			(*init_machine)(void);
+	void			(*init_late)(void);
 #ifdef CONFIG_MULTI_IRQ_HANDLER
 	void			(*handle_irq)(struct pt_regs *);
 #endif

arch/arm/kernel/setup.c

@@ -800,6 +800,14 @@ static int __init customize_machine(void)
 }
 arch_initcall(customize_machine);
 
+static int __init init_machine_late(void)
+{
+	if (machine_desc->init_late)
+		machine_desc->init_late();
+	return 0;
+}
+late_initcall(init_machine_late);
+
 #ifdef CONFIG_KEXEC
 static inline unsigned long long get_total_mem(void)
 {