powerpc/mm: Fix section mismatch for mark_reserved_regions_for_nid

mark_reserved_regions_for_nid() is only called from do_init_bootmem(),
which is in .init.text, so it must be in the same section to avoid a
section mismatch warning.
Reported-by: Subrata Modak <subrata@linux.vnet.ibm.com>
Signed-off-by: David Rientjes <rientjes@google.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

arch/powerpc/mm/numa.c

@@ -969,7 +969,7 @@ static struct notifier_block __cpuinitdata ppc64_numa_nb = {
 	.priority = 1 /* Must run before sched domains notifier. */
 };
 
-static void mark_reserved_regions_for_nid(int nid)
+static void __init mark_reserved_regions_for_nid(int nid)
 {
 	struct pglist_data *node = NODE_DATA(nid);
 	struct memblock_region *reg;