bloblist: Support relocating to a larger space

Typically in TPL/SPL the bloblist is quite small. But U-Boot proper may
want to add a lot more to it, such as ACPI tables.

Add a way to expand the bloblist by relocating it in U-Boot proper, along
with the other relocation activities.

Signed-off-by: Simon Glass <sjg@chromium.org>