[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/prom_parse.c b/arch/powerpc/kernel/prom_parse.c
index e3d036f..ba9c7c1 100644
--- a/arch/powerpc/kernel/prom_parse.c
+++ b/arch/powerpc/kernel/prom_parse.c
@@ -70,7 +70,7 @@
 	if (addrc)
 		*addrc = of_n_addr_cells(dev);
 	if (sizec)
-		*sizec = prom_n_size_cells(dev);
+		*sizec = of_n_size_cells(dev);
 }
 
 static u64 of_bus_default_map(u32 *addr, const u32 *range,
@@ -660,7 +660,7 @@
 	dma_window += cells;
 
 	prop = get_property(dn, "ibm,#dma-size-cells", NULL);
-	cells = prop ? *(u32 *)prop : prom_n_size_cells(dn);
+	cells = prop ? *(u32 *)prop : of_n_size_cells(dn);
 	*size = of_read_number(dma_window, cells);
 }