common/board_f: Fix size variable

DRAM size should use 64-bit variable when the size could be more than 4GB.
Caught and verified on P4080DS with 4GB DDR.

Signed-off-by: York Sun <yorksun@freescale.com>
Acked-by: Simon Glass <sjg@chromium.org>

common/board_f.c

@@ -194,7 +194,7 @@ static int init_func_ram(void)
 
 static int show_dram_config(void)
 {
-	ulong size;
+	unsigned long long size;
 
 #ifdef CONFIG_NR_DRAM_BANKS
 	int i;