bdinfo: Show the malloc base with the bdinfo command

bdinfo: Show the malloc base with the bdinfo command

It is useful to see the base of the malloc region. This is visible when
debugging but not in normal usage.

Add it to the global data so that it can be shown.

Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Nikhil M Jain <n-jain1@ti.com>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
Tested-by: Nikhil M Jain <n-jain1@ti.com>