tpm: add tpm_calc_ordinal_duration() wrapper

Add convenient wrapper for ordinal duration computation
to remove boiler plate if else statement over TPM2.

if (chip->flags & TPM_CHIP_FLAG_TPM2)
	tpm2_calc_ordinal_duration(chip, ordinal);
else
	tpm1_calc_ordinal_duration(chip, ordinal);

Signed-off-by: Tomas Winkler <tomas.winkler@intel.com>
Reviewed-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
Tested-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
Signed-off-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>