[ARM] S3C24XX: GPIO: Move gpiolib initialisation earlier

The arch_initcall() is too late for board initialisation to use
gpiolib when doing their machine specific initilisation via the
.init_machine callback.

Bring the file into line with the s3c64xx implementation and use
the core_initcall() to register the GPIO chips.
Signed-off-by: NBen Dooks <ben-linux@fluff.org>

arch/arm/plat-s3c24xx/gpiolib.c

@@ -165,4 +165,4 @@ static __init int s3c24xx_gpiolib_init(void)
 	return 0;
 }
 
-arch_initcall(s3c24xx_gpiolib_init);
+core_initcall(s3c24xx_gpiolib_init);