s390/numa: move numa_init_late() from device to arch_initcall

Commit 3e89e1c5 ("hugetlb: make mm and fs code explicitly non-modular")
moves hugetlb_init() from module_init to subsys_initcall.

The hugetlb_init()->hugetlb_register_node() code accesses "node->dev.kobj"
which is initialized in numa_init_late().

Since numa_init_late() is a device_initcall which is called *after*
subsys_initcall the above mentioned patch breaks NUMA on s390.

So fix this and move numa_init_late() to arch_initcall.

Fixes: 3e89e1c5 ("hugetlb: make mm and fs code explicitly non-modular")
Reviewed-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Michael Holzheu <holzheu@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>