x86: emulation: Support BLOBLIST_TABLES properly

x86: emulation: Support BLOBLIST_TABLES properly

The existing QEMU implementation mostly ignored BLOBLIST_TABLES and
allocates the bulk of the tables with malloc(). Update it to place all
tables in the bloblist. Since QEMU declares a size of 128KB regardless
of the size of its tables, this requires a larger bloblist.

Fix up the e820 table to handle this, keeping the old code as an option
for now, to assist with any future bug-fixing.

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