tpm: turn on TPM on suspend for TPM 1.x

tpm_chip_start/stop() should be also called for TPM 1.x devices on
suspend. Add that functionality back. Do not lock the chip because
it is unnecessary as there are no multiple threads using it when
doing the suspend.

Fixes: a3fbfae8 ("tpm: take TPM chip power gating out of tpm_transmit()")
Reported-by: Paul Zimmerman <pauldzim@gmail.com>
Signed-off-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
Tested-by: Domenico Andreoli <domenico.andreoli@linux.com>
Signed-off-by: James Morris <james.morris@microsoft.com>

drivers/char/tpm/tpm-interface.c

@@ -402,15 +402,13 @@ int tpm_pm_suspend(struct device *dev)
 	if (chip->flags & TPM_CHIP_FLAG_ALWAYS_POWERED)
 		return 0;
 
-	if (chip->flags & TPM_CHIP_FLAG_TPM2) {
-		mutex_lock(&chip->tpm_mutex);
-		if (!tpm_chip_start(chip)) {
+	if (!tpm_chip_start(chip)) {
+		if (chip->flags & TPM_CHIP_FLAG_TPM2)
 			tpm2_shutdown(chip, TPM2_SU_STATE);
-			tpm_chip_stop(chip);
-		}
-		mutex_unlock(&chip->tpm_mutex);
-	} else {
-		rc = tpm1_pm_suspend(chip, tpm_suspend_pcr);
+		else
+			rc = tpm1_pm_suspend(chip, tpm_suspend_pcr);
+
+		tpm_chip_stop(chip);
 	}
 
 	return rc;