x86, microcode, AMD: Rewrite patch application procedure

Limit the access to userspace only on the BSP where we load the
container, verify the patches in it and put them in the patch cache.
Then, at application time, we lookup the correct patch in the cache and
use it.

When we need to reload the userspace container, we do that over the
reload interface:

echo 1 > /sys/devices/system/cpu/microcode/reload

which reloads (a possibly newer) container from userspace and applies
then the newest patches from there.

Signed-off-by: Borislav Petkov <borislav.petkov@amd.com>
Link: http://lkml.kernel.org/r/1344361461-10076-13-git-send-email-bp@amd64.org
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>