powerpc/mm: Fix section mismatch for read_n_cells

read_n_cells() cannot be marked as .devinit.text since it is referenced
from two functions that are not in that section: of_get_lmb_size() and
hot_add_drconf_scn_to_nid().
Signed-off-by: David Rientjes <rientjes@google.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

arch/powerpc/mm/numa.c

@@ -406,7 +406,7 @@ static void __init get_n_mem_cells(int *n_addr_cells, int *n_size_cells)
 	of_node_put(memory);
 }
 
-static unsigned long __devinit read_n_cells(int n, const unsigned int **buf)
+static unsigned long read_n_cells(int n, const unsigned int **buf)
 {
 	unsigned long result = 0;