As the TPM driver can be accessed in romstage after
cache-as-ram is torn down use the cache-as-ram migration
API to dynamically determine the global variable address.
Change-Id: I149d7c130bc3677ed52282095670c07a76c34439
Signed-off-by: Aaron Durbin <adurbin@chromium.org>
Reviewed-on: http://review.coreboot.org/3233
Tested-by: build bot (Jenkins)
Reviewed-by: Stefan Reinauer <stefan.reinauer@coreboot.org>