[POWERPC] Rename prom_n_size_cells to of_n_size_cells

This is more consistent and gets us closer to the Sparc code.

Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Paul Mackerras <paulus@samba.org>

arch/powerpc/mm/numa.c

@@ -202,7 +202,7 @@ static void __init get_n_mem_cells(int *n_addr_cells, int *n_size_cells)
 		panic("numa.c: No memory nodes found!");
 
 	*n_addr_cells = of_n_addr_cells(memory);
-	*n_size_cells = prom_n_size_cells(memory);
+	*n_size_cells = of_n_size_cells(memory);
 	of_node_put(memory);
 }