m68k/amiga: Use arch_initcall() for registering platform devices

module_init() maps to device_initcall(), opening the possibility of
race conditions between platform_driver_probe() and registering platform
devices.
Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>

arch/m68k/amiga/platform.c

@@ -252,4 +252,4 @@ static int __init amiga_init_devices(void)
 	return 0;
 }
 
-device_initcall(amiga_init_devices);
+arch_initcall(amiga_init_devices);