x86: Add binary blob checksums for Minnowboard MAX

To try to reduce the pain of confusion of binary blobs, add MD5 checksums
for the current versions. This may worsen the situation as new versions
appear, but it should still be possible to obtain these versions, and thus
get a working setup.

Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>