[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>
diff --git a/arch/powerpc/kernel/setup-common.c b/arch/powerpc/kernel/setup-common.c
index f7ef5a9..640ff0d 100644
--- a/arch/powerpc/kernel/setup-common.c
+++ b/arch/powerpc/kernel/setup-common.c
@@ -380,7 +380,7 @@
 		const unsigned int *ireg;
 
 		num_addr_cell = of_n_addr_cells(dn);
-		num_size_cell = prom_n_size_cells(dn);
+		num_size_cell = of_n_size_cells(dn);
 
 		ireg = get_property(dn, "ibm,lrdr-capacity", NULL);