Currently, these functions assume #address-cells and #size-cells are
both one. Fix them to support 64bit DTB.
Also, I am fixing a buffer overrun bug while I am here. The array
size of gd->bd->bd_dram is CONFIG_NR_DRAM_BANKS. The number of
iteration in the loop should be limited by that CONFIG.
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>