Most a6xx targets have security issues that were fixed with new versions
of the microcode(s). Make sure that we are booting with a safe version of
the microcode for the target and print a message and error if not.

v2: Add more informative error messages and fix typos
Signed-off-by: Jordan Crouse <jcrouse@codeaurora.org>
Reviewed-by: Akhil P Oommen <akhilpo@codeaurora.org>
Signed-off-by: Rob Clark <robdclark@chromium.org>