ColdFire: Fix m54455EVB save environment bug

The ATMEL flash does not have buffer write feature. Assgined
buffer_size = 1, so that when there is a write to the flash
will not use buffer write function.
Signed-off-by: NTsiChung Liew <tsicliew@gmail.com>

board/freescale/m54455evb/m54455evb.c

@@ -185,7 +185,7 @@ ulong board_flash_get_legacy (ulong base, int banknum, flash_info_t * info)
 	info->flash_id          = 0x01000000;
 	info->portwidth         = 1;
 	info->chipwidth         = 1;
-	info->buffer_size       = 32;
+	info->buffer_size       = 1;
 	info->erase_blk_tout    = 16384;
 	info->write_tout        = 2;
 	info->buffer_write_tout = 5;