vboot: prevent some tests from running when MOCK_TPM=1
vboot: prevent some tests from running when MOCK_TPM=1

tlcl_tests and rollback_index2_tests only work when
MOCK_TPM is disabled.

BUG=b:124141368, chromium:972956
TEST=make clean && make runtests
BRANCH=none

Change-Id: I3d09e2b02c72e2ee1b1b89769e433cc5cd513163
Signed-off-by: Joel Kitching <c2feea8c1334a0d339e816ae4c7c9ecfa9b30a91@google.com>
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/vboot_reference/+/1776278
Reviewed-by: Joel Kitching <c2feea8c1334a0d339e816ae4c7c9ecfa9b30a91@chromium.org>
Commit-Queue: Joel Kitching <c2feea8c1334a0d339e816ae4c7c9ecfa9b30a91@chromium.org>
Tested-by: Joel Kitching <c2feea8c1334a0d339e816ae4c7c9ecfa9b30a91@chromium.org>

coreboot/vboot,coreboot/vboot,coreboot/vboot,coreboot/vboot,coreboot/vboot