Patch merged into coreboot/master: vboot: clear tpm when required

the following patch was just integrated into master:
commit 494d398ae43126aec611238a9d30c7b0020cb251
Author: Vadim Bendebury 
Date:   Wed Sep 28 18:59:39 2016 -0700

vboot: clear tpm when required

Function which invoked when TPM clear is requested was left empty,
    this patch fixes it.

BRANCH=gru
    BUG=chrome-os-partner:57411
    TEST=verified on a chromeos device that tpm is in fact cleared when
         CLEAR_TPM_OWNER_REQUEST is set by userland.

Change-Id: I4370792afd512309ecf7f4961ed4d44a04a3e2aa
    Signed-off-by: Vadim Bendebury 
    Reviewed-on: https://review.coreboot.org/16805
    Tested-by: build bot (Jenkins)
    Reviewed-by: Philipp Deppenwiese

See https://review.coreboot.org/16805 for details.

-gerrit