s390/nmi: initialize control register 0 earlier

Change machine_check_init() to an early_initcall(). This makes sure it will
be called before all other cpus are online and therfore saves us a lot of
pointless smp_call_function() calls.
The control register settings will be forwarded to the other cpus when they
will be brought online.
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Reviewed-by: Hendrik Brueckner <brueckner@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

arch/s390/kernel/nmi.c

@@ -363,4 +363,4 @@ static int __init machine_check_init(void)
 	ctl_set_bit(14, 24);	/* enable warning MCH */
 	return 0;
 }
-arch_initcall(machine_check_init);
+early_initcall(machine_check_init);