tpm: Allow tpm_tis drivers to set hwrng quality.

Adds plumbing required for drivers based on tpm_tis to set hwrng quality.

Signed-off-by: Louis Collard <louiscollard@chromium.org>
Reviewed-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
Signed-off-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>